#1 ANTLR mode + performance fix

[Kunle Odutola]

This patch adds an ANTLR mode to csflx and fixes a
performace issue where running csflex on a ~40kB file
that fully defined a few Unicode general categories
caused up to 1.2GB mem requirement. Tied up the PC for
a long while too.

Simple hack/fix was to ignore the estSize parameter
when building StateSets.

It's not really a .patch file, just a collection of
changed files.

[Kunle Odutola]

ANTLR mode patch