replaced my diff method with the simplify method from the BDD library
Using the standard BDD package (JDD) it was used all the time as default fallback; now the error message does not appear anymore
Method for counting operators in FeatureExpression when printed based on a BDD
statistics for presence condition simplification in ifdeftoif
Merge remote-tracking branch 'origin/master' into ldv-gen
ifdeftoif statistics output
Merge branches 'ldv-gen' and 'master' of https://github.com/aJanker/TypeChef into ldv-gen
debug output in IfdefToIfTest
Merge remote-tracking branch 'origin/master' into ldv-gen
Merge remote-tracking branch 'origin/master' into ldv-gen
Merge remote-tracking branch 'origin/master' into ldv-gen

Conflicts:
	CRewrite/src/main/scala/de/fosd/typechef/crewrite/IfdefToIf.scala
	CRewrite/src/test/scala/de/fosd/typechef/crewrite/IfdefToIfTest.scala
Merge remote-tracking branch 'origin/master' into ldv-gen
corrected path in IfdeftoifTest
merging ckaestne/master
fix compile errors; add todos for incompatible code (does not compile)
cleanup imports
update ifdeftoif description
add missing import; organize imports
remove unnecessary constant; update comment
renaming refactoring