Re: ICU integration

Updated patch attached.

The previous round of reviews showed that there was general agreement on
the approach. So I have focused on filling in the gaps, added ICU
support to all the locale-using places, added documentation, fixed some
minor issues that have been pointed out. Everything appears to work
correctly now, and the user-facing feature set is pretty well-rounded.

I don't have much experience with the abbreviated key stuff. I have
filled in what I think should work, but it needs detailed review.

Similarly, some of the stuff in the regular expression code was hacked
in blindly.

One minor problem is that we now support adding any-encoding collation
entries, which violates some of the comments in CollationCreate(). See
FIXME there. It doesn't seem worth major contortions to fix that; maybe
it just has to be documented better.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services