address PR review comments
relax thread containment
add packages & multi-source test cases
fix merge errors

Conflicts:
	org.scala-ide.sdt.core.tests/src/scala/tools/eclipse/completion/CompletionTests.scala
	org.scala-ide.sdt.core/src-2_11/scala/tools/eclipse/ScaladocGlobalCompatibilityTrait.scala
	org.scala-ide.sdt.core/src/scala/tools/eclipse/LocateSymbol.scala
	org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaHover.scala
	org.scala-ide.sdt.core/src/scala/tools/eclipse/ui/ScalaCompletionProposal.scala
Simplified parsedDocComment

Conflicts:
	org.scala-ide.sdt.core/src/scala/tools/eclipse/ui/ScalaCompletionProposal.scala
Constraining the use of getJavaElement
Makes legacy locate available again