Fixed Jetpack ID sync on REST

Added an extra check for `dotComID` before using REST, and enabled
Jetpack REST for internal builds again
Add scheme, host when opening relative URLs.
Merge branch 'release/4.6' into issue/2705-fix-jetpack-options-sync
Merge branch 'issue/408-Remove-Location-Metadata-From-Exif' into release/4.6

Conflicts:
	Podfile
	Podfile.lock
	WordPress/Classes/Services/MediaService.m
Fix merge error.
Update test logic to reflect new REST API featured image format.
Remove search for attachments for featured image test.

The featuredImageFromPostDictionary no longer searches on attachments it goes directly to the content of the post.
Make defaultAccount a variable to make it easier to debug.

It looks there is race condition between this test and the simulator starting the app or the saving of the context.
When pausing for debug the test they succeed if they run without pause they fail.
Refactor Jetpack REST checks into separate method
Merge pull request #2708 from wordpress-mobile/issue/2705-fix-jetpack-options-sync

Fixed Jetpack ID sync on REST
Updated podfile to pull in editor fix; added...

...array to track ids of all media currently in process of being inserted into a post.
Added a WPUploadStatusButton with new uploading text
Dialog box text update for cancelling media in the new editor.
Add a WPMediaProcessor to handle all resizing and export of assets in the background.
Fix code layout of methods.
Remove unused methods.
Show better error messages when media fails when exporting.
Increase maximum number of images.
While uploading feature image don't allow to select another one.
Code layout fix.