Add functionality to upload videos to server using XMLRPC.
Do not delete file because streaming requests.

When doing streaming requests this file cannot be deleted on dealloc because when the HTTP request tries to get it it streamed it can already be deleted.
Convert request to streaming one because the request size when uploading videos can easily put to much memory pressure on the app.
Fix issues when blogs don't have any post on them that cause a exception because of nil predicates.
Fix answers when not a WP.com blog and no valid return is found on response.
Check if videopress is available before making videos available on picker.
Improve fix for crash on startup.
Add documentation and extra methods to check if optimisation should be done.

At the moment optimisation is done if the original asset is bigger than 20Mb and if an user settings is enabled.
Add documentation for method CreateVideoMediaWithAsset
Allows only one video to be selected.

Improved error/information when video press isn't enabled.
Relayout of method for improved readability.
Improve KVO code for mediaUploadQueue.
Take in account long times for video processing to lower resolutions.
Only force RPC for video if it's a WP.com blog.
Make user pick if he wants to resize the videos before sending them.
Merge branch 'develop' into issues/1792-Support_for_uploading_videos

Conflicts:
	WordPress/Classes/Services/ReaderPostService.m
	WordPress/WordPress.xcodeproj/project.pbxproj
Remove log message
Clean video list after starting export/upload process
Re add the WPVideoOptimizer class that got lost in the merge process.
Merge branch 'develop' into issues/1792-Support_for_uploading_videos

Conflicts:
	WordPress/Classes/ViewRelated/Post/EditPostViewController.m
	WordPress/WordPress.xcodeproj/project.pbxproj