Quick and dirty adapter to dep_selector
Add problem dump and benchmarks
Pass solve version and constraint types to dep-selector
Install gecode on travis so dep-selector can work
Drop jruby because dep-selector uses C extensions
Clean up benchmarks
Reorganize gecode solver to group internal methods and make them private
Remove GecodeSolver#dump_problem

GecodeSolver should be compatible with the existing serializer, which
does basically the same thing (except JSON instead of ruby literals)
Use published dep-selector gem (still prerelease)
Document GecodeSolver
Add tests for GecodeSolver primary API
Optimize Constraint to not create new Versions unnecessarily
Fix code consistency and doc issues w/ GecodeSolver
Extract Version coercion to a class method
Remove demands debug code (for now)

Need to get consensus on the best location and behavior of this feature,
and it's not necessary for now.
Merge branch 'gecode-solve'

fixes https://github.com/berkshelf/solve/issues/31
https://github.com/berkshelf/solve/pull/33
Update .travis.yml to test on Ruby 1.9 and use parallel jobs
Gitignore .rspec
Run specs in a random order

Running the specs in a random order will help us uncover order-dependent
tests.
Use a constant to keep track of the default constraint (>= 0.0.0)