feat(tasks): Task assignment implemented.

SD-728
SD-733
fix(tasks): fixed minor issues.
fix(desks): Fixed desks service.
fix(planning): Updated coverages to use new assignee-box.
feat(desks): add wizard for desk editing
feat(desks): fix message handling in wizard
fix(desks): improve the code for adding desks
Merge remote-tracking branch 'upstream/devel' into devel
fix(desks): rebase and fix wizard first step
fix(grunt): make grunt server listen to 0.0.0.0

it was set to localhost only which doesn't work within docker image
feat(preferences): frontend logic for user preferences
fix(preferences): improve the code
wip(docker)
fix(docker)
Merge branch 'fix-connect' of github.com:petrjasek/superdesk-client into add-docker
readme: added info about docker
repo: added vagrant and according readme lines
feat(api): add resource.remove
Merge remote-tracking branch 'petr/fix-connect' into devel
Merge remote-tracking branch 'yauhen/add-vagrant' into devel