renamed ModelFromC to ExecutableModel, this will the the new abstract executable model interface

git-svn-id: https://roadrunnerlib.googlecode.com/svn/branches/refactor_modelgen@879 c0027639-9190-0b57-01eb-f09a03790dae
partial refactor of model generation

git-svn-id: https://roadrunnerlib.googlecode.com/svn/branches/refactor_modelgen@880 c0027639-9190-0b57-01eb-f09a03790dae
Merge branch 'git-refactor-modelgen' of github.com:AndySomogyi/roadrunner into git-refactor-modelgen