* ref(large-video): permanently enable canvas based background

* squash: leave flag for disabling background

To reduce the amount of motion that has to be blurred, use a canvas
to essentially set the FPS of the video background. This canvas
component is behind a temporary feature flag, as well as being able
to disable the blur, so it can be played around with on deployed
environments.

The animation for toggling filmstrip visibility was lagging on
Safari. Even though the background video is set to hidden, it is
still causing issues. Setting the background to display none
instead does help but might interfere with animations. So instead
do the easy thing and re-use logic used for Firefox to not show
the background video.

* ref(large-video): reactify background

This is pre-requisite work for disabling the background on
certain browsers, namely Firefox. By moving the component
to react, and in general encapsulating background logic,
selectively disabling the background will be easier.

The component was left for LargeVideo to update so it can
continue to coordinate update timing with the actual large
video display. If the background were moved completely into
react and redux with LargeVideo, then background updates would
occur before large video updates causing visual jank.

* fix(large-video): do not show background for Firefox and temasys

Firefox has performance issues with adding filter effects on
animated elements. On temasys, the background videos weren't
really displaying anyway.

* some props refactoring

Instead of passing in classes to LargeVideoBackground, rely on
explicit props. At some point LargeVideo will have to be reactified
and the relationsihp between it and LargeVideoBackground might
change, so for now make use of props to be explicit about
how LargeVideoBackground can be modified.

Also, set the jitsiTrack to display on LargeVideoBackground to
null if the background is not displayed. This was an existing
optimization, although previously done with pausing and playing.

* squash: use newly exposed RTCBrowserType

* squash: rebase and use new lib browser util

* squash: move hiding logic all into LargeVideo

* squash: remove hiding of background on stream change. hopefully doesnt break anything

- Modify Etherpad and SharedVideo so their resizing takes into account
  the width of the filmstrip in vertical filmstrip mode.
- Modify Filmstrip's getFilmstripWidth to account for when the filmstrip
  is hidden.
- modify VideoContainer so in vertical filmstrip mode it centers the
  shared desktop stream in the middle of the available space not taken
  by filmstrip.
- Also allow clickthrough on the secondary toolbar itself while still
  allowing clicks on the toolbar's buttons. This allows clicks on
  shared videos to go through.

Prepares for the latest eslint & flow-related npm packages which cause
these errors.

ESLint 4.8.0 discovers a lot of error related to formatting. While I
tried to fix as many of them as possible, a portion of them actually go
against our coding style. In such a case, I've disabled the indent rule
which effectively leaves it as it was before ESLint 4.8.0.

Additionally, remove jshint because it's becoming a nuisance with its
lack of understanding of ES2015+.

* feat(presence): display status in thumbnail and large video

- Create a React Component for displaying presence. It currently
  connects to the store for participant updates but in the future
  should not be as smart once more reactification occurs.
- Modify filmstrip css so the presence status displays horizontal
  center and below the avatar.
- Modify videolayout css so the presence status displays horizontal
  centered and with a rounded background.
- Dispatch presence updates so the participant state can be update.
- Update message position on large video update to ensure message
  positioning is correct.

* squash: do not show presence message if connection message is displayed

The container needs to store user's ID in order for the 'isOnLargeVideo'
logic to work correctly when user has no stream (previously it was
obtained from stream which can be null/undefined).

When using onplay in firefox, the event fires before data is flowing,
which can cause videoHeight and videoWidth to be 0 during resizing.
By using onplaying, there is some assurance data is being received,
so videoHeight and videoWidth should be set.

We seemed to be using the names "film strip" and "filmstrip" (and,
consequently, their source code-conscious forms such as film-strip,
FilmStrip, etc.) In order to comply with our coding style which requires
a consistent one name for a given abstraction, choose one name and
rename the uses of the other name.

Wikipedia has a definition of a "filmstrip", I couldn't find a "film
strip". I guess our abstraction can be seen as what's described there.
When I google "film strip", I get results about "filmstrip" at the top.
That's why I chose "filmstrip".

Certain uses of "film strip" such as interfaceConfig.filmStripOnly and
in the external API I left untouched in an attempt to preserve
compatibility.

I wasn't sure whether CSS was tangled in compatibility so I made a
choice and renamed there was well.

Enable ESLint on jitsi-meet with the same configuration and the same
goals as in lib-jitsi-meet.

Grey filter will be applied to the remote video/avatar displayed on
"large" and a message indicating remote connectivity issues will be
shown on top of that.

The 'wasVideoRendered' flag will tell whether or not we have any video
image rendered(even if stalled) on the large video element.

Only the VideoContainer is interested in showing the video problems
filter which is meant to be displayed when ICE is disconnected.

VideoContainer is a separate being which implements the LargeContainer
and it's confusing to have it in the same file. This was encouraging to
access private parts of the VideoContainer directly(not through
the interface).

When link is missing disable clicking.