LB-8: Tageswoche livedesk:mobile issues (IOS)

fixed default theme.
revert LB-56 : Add the source key to the Source(superdesk-source) model
Made ffmpeg the default thumbnail generator

We still have issues with GraphicsMagick not working on different systems
LB-306 : Change names of users and live blog in default demo database
LB-306 : Change names of users and live blog in default demo database
LB-349: Share functionality does not work on default embed templates

Embed now has default theme.
LB-433 : Twitter search: urls in a tweet

Done
Removed dependency between livedesk plugin and content-article

The blog post service was using the AsLikeAll criteria from the
content-article plugin.
LB-425: Integration with SMS Gateway
* some simple attempt
LB-499: Add provider no action

Use xfilter for creating new providers so it gets
data needed for rendering.
LB-499: Add provider no action

Fix external blogs rendering when provider url is changed.
LB-499: Add provider no action

Fix subscribed blogs lookup.
LB-425: Integration with SMS Gateway
* adjusting, testing
LB-542: Embed URL can't be opened in IE8 and IE9

Fixed with a polyfill. From what I was the problem was just in IE8
Merge pull request #29 from vladnicoara/liveblog-13-ie

LB-542: Embed URL can't be opened in IE8 and IE9
Merge pull request #27 from vladnicoara/stt-issues

Stt issues
LB-425: Integration with SMS Gateway
* services for feeds
LB-508 : Autopublish - chaining blogs plugin
LB-425: Integration with SMS Gateway
* adjusted
Merge branch 'devel' into lb-425-sms-gateway