Up until now we relied on implicit loading of middlewares and reducers, through
having imports in each feature's index.js.

This leads to many complex import cycles which result in (sometimes) hard to fix
bugs in addition to (often) breaking mobile because a web-only feature gets
imported on mobile too, thanks to the implicit loading.

This PR changes that to make the process explicit. Both middlewares and reducers
are imported in a single place, the app entrypoint. They have been divided into
3 categories: any, web and native, which represent each of the platforms
  respectively.

Ideally no feature should have an index.js exporting actions, action types and
components, but that's a larger ordeal, so this is just the first step in
getting there. In order to both set example and avoid large cycles the app
feature has been refactored to not have an idex.js itself.

* Fix LoginDialog hidden by gUM-Overlay

Running FF46 on Linux and Android. The gUM Dialog (zIndex 1013) hides the LoginDialog (zIndex 999 by default) , but the gUM Dialog will only be resolved when connection is completed (aka hideUserMediaPermissionsGuidanceOverlay is called once the Promise.all in createInitialLocalTracksAndConnect is resolved and that Promise includes "connect").

Fix this by increasing the connection dialog zIndex.

Alternatively this could by fixed by handling gUM and connection one after the other.

* remove whitespace change

* ref(notifications): convert some dialogs to error or warning notifications

- Expand the configurability of the Notification component so warnings
  and errors can be displayed.
- Allow Notification to take in arbitrary text for the body.
- Rename defaultTitleKey to titleKey for consistency with descriptionKey.

* ref(notifications): remove openReportDialog method

openReportDialog is a wrapper around showError that adds
a logger statement. It is being called in one place only
so remove the method and have that one place call logger.

* ref(notifications): UI.showTrackNotWorkingDialog takes a boolean

Change UI.showTrackNotWorkingDialog so it takes a boolean
arguments instead of the entire track. A small refactor so
the method needs to know less.

* [squash] Fixes eslint errors

* WiP: Fixes desktop sharing error strings and adds support button

* [squash] Fix icons appearances

* [squash] Fix translate titles and messages

* [squash] fix(translation): Fixes incorrect password string

* [squash] fix(recording): Fixes recording message

* [squash] fix(warning): Turns some warnings to errors and makes support link optional.

* [squash] fix(translation): Addressing language comments

* [squash] Fixes jsdoc and formatting

* [squash] fix(noopener): Fixes window.open noopener

* [squash] fix(constants): Extract constants and refactor NotificationWithToggle

* [squash] fix(lang): Fixes camera and mic error titles

* [squash] fix(supportLink): Renames addSupportLink to hideErrorSupportLink

By default impromptu uses the first state as the default one to show.

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+.

Removing translateString forces using data-i18n attributes, to make sure we do not forget to set them. Missing data-i18n attributes is a problem with late loading where we can end up without translation, without text. Missing data-i18n attributes is also problem that strings will not be translated when changing language.
Fixes a bug in invite dialog, where remove password button was shown for non moderators.

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

Clears the password if user cancel attempt to enter password, as using one instance of locker for multiple attempts keeps the password.