Fixed gemspec.
Don't try to load the AST.
Use correct superclasses in Evaluator.
Fixed some constant scopes.
Imported changes from Rubinius.
Fixed constant scoping.
Allow dynamic resolution of CompileError constant.
Use ToolSet constant to reference tool set components.
Scope non-toolset classes to Rubinius.
Update gemspec.
Fixed scope reference of constants.
Require rubinius/toolset in gemspec.
Removed required Ruby version.

The rubinius build gems have to run on multiple Ruby versions.