bug#16481: dfa.c and Rational Range Interpretation

[Paul Eggert]

It seems that the issues in this bug report are all done in the savannah 
git master for grep, so I'm marking this as done.

At some point I'd like to change the regex code to support RRI, at which 
point the dfa.c should now automatically adapt without our having to 
change dfa.c further.  But that would be a matter for a gnulib and/or 
glibc bug report, not dfa and/or grep.