* Pulled in @havenwood's chruby man page.

* This will allow overriding the default ruby matching logic with custom searching
  algorithms.

* This will allow overriding chruby_list with custom ruby listing logic.

…s paths with spaces.

* Customization of `CHRUBY_RUBIES` array should be done in `chruby_init`.

… search.

* Added `chruby_list` to list the contents of `CHRUBY_DIRS`.
* Removed `chruby_init` and the `--reload` option.
* This prevents having to restart the shell after installing a
  new ruby.