List[Id] -> List[Opt[Id]] for renaming
Merge branch 'andreasmaster' into jl
make shadowing check variability-aware
make typedef shadowing check variability-aware too
merge isshadowing checks for varenv and typedefenv
remove unnecessary imports
use variable control flow graphs to determine bad input selections for extract function
cleanup import list; remove several intellij warnings
renaming refactoring
use specific error messages in gui-view when renaming identifiers fails
fix typo
renaming refactoring; code layout
Merge branch 'jl'

Conflicts:
	CRefactor/src/main/scala/de/fosd/typechef/crefactor/backend/engine/CExtractFunction.scala