Updated .gitignore.
Removed versions for rubysl gems in Gemfile.

The installed gems should resolve these dependencies but the versions of
those installed gems will depend on whether Rubinius 2.x (2.1 compat) or
Rubinius 1.3+ (1.8.7 compat) is being used.
Switched profiler, coverage, debugger gem versions.

Generally, gems for Rubinius 2.x are 2.x and for Rubinius 1.3+ are 1.x. However,
these tools are general and likely will not depend on language versions. To reduce
effort, we'll use the 2.x versions until there are such problems that would make
it easier to have separate versions.
Removed obsolete web directory.
Updated README.