Merged, thanks

Leon/slf4j log bridge

update to Isabelle2016

Quantifier improvements + invariant preservation in program transforms

update to libisabelle 0.3

print verification report after Isabelle phase

Added integration/evaluators/AbstractEvaluatorSuite.scala

5f9356bf broke this, but I can't blame @manoskouk, the code was indeed
messy.

(b) Fixing bugs in the benchmarks
(c) Makinging transformation phases of Orb ignore parts of the library

 * Expression grammars are now alwayse 'Labels -> Expr', simple grammars
   that are 'Type -> Expr' can simply extend SimpleExpressionGrammars

 * Labels now have Aspects. A label aspect describes a particular
   feature of the label (e.g. its size), as well as how this aspect
   applies to sub-productions.

   Aspects describe how sub-productions are generated/filtered/modified.
   See comments in Aspect for more information