Moving to distutils.
Update solver import for new package layout.
Remove custom libxml compilation. Print list of successful solvers and ignore (but warn) about other interfaces which weren't built.
Fix warehouse example for better solver import.
Remove unused variable in Gurobi interface.
Print message about disable solvers at the end of run instead of start.
Support for compiling SCIP interface under distutils.

Also make it easier to use SCIP by extracting and compiling if scipoptsuite-?.?.?.tgz is placed in the Numberjack folder.
Remove CPLEX and Gurobi interfaces from available_interfaces, since they have been moved to Numberjack.solvers now.
Tidy comment.
Update readme for new distutils build procedure.
Add LGPL v2 license text.
Silence some warning flags for external code.
Comments for manifest.in

Also fix MiniSat source path.
gitignore dist and MANIFEST.
Move some compiler flags to be linux only.
Include examples in distribution manifest and exclude some folders of the solvers that we don't use.
Allow tests to be run with new import location.

We need to find a testing framework which will be able to test for different solvers.
Raise exception is xml2-config could not be found.
remove manifest.in from manifest.in
Move available_sovlers to Numberjack.solvers package.