Speeds up find(AllBindings|AllTreesWithSamePosition|SymbolForImportSelector)

cosmetics
fixes #1001905
Merge pull request #32 from huitseeker/speedy-pimps

Speeds up find(AllBindings|AllTreesWithSamePosition|SymbolForImportSelector)
Slightly improved pretty printing of Blocks.

This benefits Extract Method and similar refactorings.
Merge branch 'master' of https://github.com/scala-ide/scala-refactoring into feature-extractClosure
adopt improvements of code gen to unit tests