group reset problem.  in the meantime, I added some
optimizations:

- added "inline" directive to LOCAL

  (this assumes that AC_C_INLINE does what it's
  supposed to do).  to compile SRE on a non-unix
  platform that doesn't support inline, you have
  to add a "#define inline" somewhere...

- added code to generate a SRE_OP_INFO primitive

- added code to do fast prefix search

  (enabled by the USE_FAST_SEARCH define; default
  is on, in this release)