InternalBuilder fails if there are errors

Change-Id: I6fc4dc9e0926522cd9aba3d71f63d31a646dfeb5
don't echo all jars from TP in fundbugs

Change-Id: Id36673d000bb0c75c8fd3ead7ae23f8ff4ba5247
task 18: allow use of return in auxiliary functions 

https://github.com/LorenzoBettini/xsemantics/issues/issue/18

Fixes #18

Change-Id: Ibd023249f46d0764f60a1b38e53b2e59c5c8d0c0