Fix Ruby warnings

Start of fixing warnings provided by Ruby.

Still a **WIP** not ready to merge yet.

Ruby versions:

- [x] 2.1.2
- [ ] 2.1.1
- [ ] 2.1.0
- [ ] 2.0.0
- [x] 1.9.3
- [ ] 1.9.2
- [ ] 1.8.7

- Resolves #1088
`--warnings` sets `$VERBOSE`:

https://github.com/rspec/rspec-core/blob/26698e46d312802483cee456610508f92a3dde56/lib/rspec/core/option_parser.rb#L137

Maybe try setting that in your ruby script rather than using `-w`?