Fix NPE in GitResourceVariantTreeSubscriber.roots()

Bug: 451476
Change-Id: Iaf5e020a2762cb818eece8133b374d0158737465
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
[rebaseView] Prevent SWTException if tree is disposed

Bug: 451754
Change-Id: I41792361688dbad31d0b68021724e0909aa3615e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Change feature name of mylyn feature to simplify finding it

If "Group itemy by category" is unchecked in the p2 installation and
update UI this makes it easier to spot the EGit related features since
they will be shown close to each other in this view which is sorted
alphabetically by default.

See: https://dev.eclipse.org/mhonarc/lists/cross-project-issues-dev/msg11275.html
Change-Id: I9c87f122d199871bb44fab2cc068003fcb613346
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Merge "Fix NPE in GitResourceVariantTreeSubscriber.roots()"
Merge "[rebaseView] Prevent SWTException if tree is disposed"
Merge "Change feature name of mylyn feature to simplify finding it"
[repoView] Fix ClassCastException on add to index on folder

The following steps lead to a ClassCastException
- select a folder in git repositories view which contains some dirty
  file
- click "Add to index" on this folder in the repositories view

Bug: 447611
Change-Id: Ic902775b12c65177131e7f5d10291bb6a5cd83f8
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>