TreeGrammarDecomposition: fixed bug in latex debug output, fixed a bug not producing minimal grammar, forgot to add production rules \alpha_0 => trivialKey (where trivialKey = q \in L)

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2224 85d21ef8-add0-11de-ae77-5bfb9c5a3f34