Add support for Ruby bang and question methods

* The ::find method of tag-reader.coffee uses getCurrentWordBufferRange()
  to pull in the current word to pull in the current tag. Passing in a
  custom regexp to getCurrentWordBufferRange() determines what constitutes
  a word.

* By slightly modifying the default regexp used (from Cursor::wordRegExp),
  we can pull in 'words' that have either a ? or ! at the end of the method,
  which is common in the Ruby programming language.

* This resolves issue #32.
This might be a single cleaner:

```coffee
return editor.getTextInRange([range.end, range.end.translate([0, 1])])
```