In order to be able to add analytics to the deep-linking pages the
lib-jitsi-meet initialization has been moved so it happens earlier.

The introduced `initPromise` will eventually disappear, once conference is
migrated into React and / or support for Temasys is dropped. At that stage, it
can be turned into a sync function which all platforms share.

* feat(Deeplinking): Implement for web.

* ref(unsupported_browser): Move the mobile version to deeplinking feature

* feat(deeplinking_mobile): Redesign.

* fix(deeplinking): Use interface.NATIVE_APP_NAME.

* feat(dial_in_summary): Add the PIN to the number link.

* fix(deep_linking): Handle use case when there isn't deep linking image.

* fix(deep_linking): css

* fix(deep_linking): deeplink -> "deep linking"

* fix(deeplinking_css): Remove position: fixed

* docs(deeplinking): Add comment for the openWebApp action.

Do not include the protocol part in the intent URL.

For the static page an error message displays stating no room
was specified. On mobile for unsupported browsers, the dial in
info will not show.

- Move the existing components for the static dial in page into
  a separate folder for easier reuse.
- Reuse those components for displaying dial-on numbers on the
  mobile page for unsupported browsers.
- Modify those components to support having tel protocol
  links on the dial-in numbers.
- Have DialInSummary, formerly DialInInfoPage, respect a
  passed in className prop for easier styling differences.

Prepare for React 16.

Split language detectors to be web/native dependent. Take care of strings that contain html.

Until we make a decision on access modifier hints and adopt a respective
coding style, consistency is king.

The desired behavior of the button 'Start a conference' / 'Join the
conversation' is to launch the mobile app if installed; otherwise, do
nothing i.e. continue to display UnsupportedMobileBrowser.

Anyway, we may change our minds about allowing the user to continue in a
supported mobile browser so preserve the source code that enables that
but give it more appropriate naming.

React Native provides a Platform abstraction which React does not
provide.