moved Sampling subproject to separate repository: https://github.com/ckaestne/TypeChef-Sampling
removed old unused code
update to new sat4j version
alternative implementation of BDD-to-CNF translation

uses more variables but avoids exponential explosion
partially undo change a2ef0fde996aa2

this implementation of checking of GnuAsmExpr has side effects. It produces tons of error messages in Linux.
We should never blindly search for ids. Currently we accept to not understand GnuAsmExpr in details, that's why there is the untyped "stuff" variable. If we want to handle this, we need to handle this properly and change the AST node and properly typecheck it.

Added test that catches this issue
update sbt version, disable crossbuild for old versions
fix test case