Added some special code to deal with logical symbols defined in multiple layers.
Fixes issue 253.


git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2176 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
some changes to ceres omega, replaced custom string conversion methods for list by the builtin mkString method (FSequent,Sequent,Grammar)

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2177 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
TreeGrammarDecomposition: refactored propositional representation of MinCostSAT formulation, improved debug messages
added integrations tests for TreeGrammarDecomposition in TreeGrammarDecompositionTest.scala

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2178 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
Added a guard that checks whether MaxSAT is installed, otherwise it would not compile on my system.


git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2179 85d21ef8-add0-11de-ae77-5bfb9c5a3f34