Add date changing capability to stop time
Add StopTimeDialog file to Resources.layout
Fix 24h format bug in time entry editing menu
Description edit cursor jumping on sync. Closes #181
Merge pull request #202  from toggl/taavirehemagi-editstopdatetime

Adds date picker to stop time dialog fragment. Closes #191.

Conflicts:
	Joey/UI/Fragments/ChangeTimeEntryStartTimeDialogFragment.cs
Merge pull request #204 from toggl/taavirehemagi-cursorjumpdescription

Description edit cursor jumping on sync. Closes #181
Remove unused ValidationContext class.
Tmp commit.