From the spec ? and ! are only allow at the _end_ of _method_ names. The current highlighter accepts ? and ! in _all_ identifiers (since they could be e.g. method calls), too.
New features are:
- TODO (and FIXME, BUG, XXX) highlight in oneline comments (bold green)
- :symbols support (red)
- proc block argument highlight for e.g. |arg,val| (yellow, disabled)
- class member highlight for e.g. @field (brown, disabled)
- additional quasi-keywords
Disabled features may be enabled by setting a color in the header.