* Adds a hook to insert body html.

* Adds a hook to insert head html.

* feat(welcome): new design

* squash: update strings

* squash: copy/paste error?

* squash: remove welcome page disabling checks

* squash: change strings again

* squash: background var

* squash: title and desc css as variables

Currently all.css is loaded after app.js. This means there may
not be a guarantee that the css is loaded before the js, which
is bad because the js does dom querying for sizes on elements,
but some element sizes will be affected by js. So instead load
css upfront and let the browser block as needed or at least
give the css a head start in racing javascript to load.

* feat(keyboard-shortcuts): show help in a react dialog

- Move shortcut help dom declaration to a react component
- Let open/close logic be handled by AtlasKit Dialog
- Remove static html for help from index.html
- Consolidate keyboard shortcut css

* squash: use lozenge for key styling

* squash: use different iteration style

* squash: update package-lock for lozenge

* include local.html file meant to define local analytics properties
include all specified local analytics properties in analytics events

* use new variable name jitsiDeploymentInfo to represent more general use as local deployment information collection

Also clears debian package from including *.js files from source roote folder, files which were not used.

Adds a placeholder which allows to write a plugin for executing some
code after the "load error handler" is triggered. A function named
"postLoadErrorHandler" should be defined in one of
the "#include virtual" files.

If the page reload value is not within specific range it will be
adjusted to a default of 10 seconds.

Also adds a link to reload manually.

The page will be reloaded if any of the mandatory scripts/resources
fails to load. The reload will be delayed with exponential backoff
starting from 2 seconds. The retry attempt counter is passed as
'rCounter' query attribute.

The commit adds an error listener which will replace the document body
with an error message if any of the files required for the app to
be displayed correctly fails to load.

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.

Renames 'videoConnectionMessage' to 'localConnectionMessage', because
it is displayed when we're having problems with our local connection
and a different one will be shown for the remote connectivity issues.

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.