Remove _ and - as word constituents.

As a consequence it made the siglled variable regexp a bit longer, which
is the only thing that nonstandard definition of _ and - accomplished. I
removed it unless/until it truly becomes necessary.
Improved types highlighting

Now will highlight things like int, int8, and int64 (all the way to
int999) for the included native types. Also commented out the debug
messages to make the indent code slightly faster (not wasting time
printing all that stuff).