Make the Onigmo patch obsolete

[herwinw]

One of my "I want to do this some day but not right now" tasks.

We currently have a one line patch for Onigmo to enable the use of uppercase letters in capture group names, but disable the Ruby bindings.

It would be nice if we could push a patch upstream to split this compile option, where defining RUBY would imply the extra range of capture groups, but it should be possible to enable that extra range separately.