Added "bashe" alias for editing global bash environment variables.
Removed temporary solution for JRuby 2.0 compatibility.

- Same effect can be achieved by adding a global `JRUBY_OPTS=--2.0`
  environment variable which affects JRuby only.
Added Git pre-commit hook for preventing Gemfile path statements.

- Examples: Using `path:` or `:path =>` will prevent the commit and
  display a warning message.