LB-856: The DB-upgrade causes errors if SQLite3 engine is used
* calmed
LB-855: Delete the population of root user
* root user not populated
LB-860: On Manage Collaborators -> add new collaborators, it is showed only first 20 collaborators.
* limit-filter added
Merge branch 'liveblog-15' into lb-860-limits-for-collab-list

Conflicts:
	plugins/livedesk/livedesk/impl/blog_collaborator.py
LB-863: After a blog is closed it should disappear from Live Blog menu

Filter closed blogs from live blogs submenu.
Merge pull request #271 from msat-cont/lb-860-limits-for-collab-list

LB-860: limits for collab list
Merge pull request #262 from msat-cont/lb-855-root-not-wanted

LB-855: root not wanted
LB-856: The DB-upgrade causes errors if SQLite3 engine is used
* try blocks adjusted
Merge pull request #260 from msat-cont/lb-856-calm-db-upgrade-under-sqlite

LB-856: calm db upgrade under sqlite
Merge pull request #279 from petrjasek/lb-863-filter-closed-blogs

LB-863: After a blog is closed it should disappear from Live Blog menu
LB-894: Twitter is not working because the proxy server is down

Provide sourcefabric cors proxy url.
Merge pull request #284 from petrjasek/lb-894-twitter-cors

Lb 894 twitter cors