Remove -1 from Mistral2 verbosity.
AllDiffExcept0 constraint.

Currently not supported by any underlying solvers, so is decomposed.
Merge branch 'master' of github.com:eomahony/Numberjack
Minor fixes to support compiling Mistral & MiniSat under latest clang and g++.

Remove printXML as it is not used.
DVONoOrder::select is not defined inline as it gave issues with all class method being given in the class definition.
MiniSat Clause_new had to be defined in class definition and specified outside.