'Add explicit type' quick assist.
Added source folder wizard in Scala perspective menu

Fix #1001577
Review by @huitseeker
Merge pull request #577 from uqbar-project/new-source-folder-menu-1001577

[1001577] - Added source folder wizzard in Scala perspective menu
Fixing MatchError on Watch Expression View by defining a default icon.

Fix #1001933
Merge pull request #578 from uqbar-project/match-error-on-watch-expression-1001933

Fixing MatchError on Watch Expression View by defining a default icon.
Merge pull request #567 from dragos/improvement/quick-fix-return-type

'Add explicit type' quick assist.
Bumps scala version to 2.10.4-SNAPSHOT
Merge pull request #579 from skyluc/issue/old-scala-snapshot

Bumps scala version to 2.10.4-SNAPSHOT