fixed EDU-236 Open first task after project creation
fixed NPE while opening first task in new study project
EDU-232 Cancel task window text editing actually doesn't work
EDU-234 Generated python file becomes visible after .answer file was deleted
Update test of JSON's structure view (broken after IDEA-131495)
open first task: refresh directory, stop with project dispose
Merge remote-tracking branch 'origin/master'
[git] make some git push classes & methods public by request of gerrit plugin author
[push] IDEA-130622 Temporary fix for "confusing selection" problem: select all repositories with commits.
[vcs] cleanup: String.format() to ease reading
[vcs] Don't notify about "less interesting" unregistered roots

IDEA-87769 roots not under project dir;
IDEA-98781 roots under ignored directories.

But still show them in the Settings.
[vcs] IDEA-131859 Fix grammar
IDEA-130848 Push dialog initial selection & enabling policy

* remember unselected roots and store in workspace.xml;
* don't select and don't load excludedRoots;
* always enable push button for mercurial;
* load all repos for git exclude remembered;
* wait until all or one repo loaded according to sync branch settings;
* always allow push for git new branch;
* preselect git repos only from project view and ignore current editor 'selection'
IDEABKL-6086 Distraction Free mode
catch AbstractMethodError for old api clients
fixed EDU-233, switched to flat model in offset listener
load all roots for git and for sync hg