Updates to be compatible with Scala IDE master

Update to latest version of plugin-profiles to use Scala 2.11.1
Add direct dependency to scala-xml and scala-parser-combinators
Some cleanup ahead of API work.

Unused imports, members, and deprecations.

Didn't touch
TemplateCompilationunitTest/ActionContentAssistProcessorTest, for
which tests fail already anyway.
More linting, bugfixing

Conflicts:
	org.scala-ide.play2/src/org/scalaide/play2/templateeditor/compiler/CompilerUsing.scala
Merge pull request #216 from huitseeker/issue/API

Some cleanup, ahead of API work