ecpg localization

Hi,

One of the few parts of the core that is not localized is the ecpg.
Attached is a patch that builds the basic infrastructure to make it
possible. Besides that I worked on some strings to make them conform
with [1] but I didn't do for all of them.
When I was doing the clean up I realized that an overhaul of ecpg_log,
ecpg_raise, mmerror and base_yyerror functions is necessary. I'll give
it a try later.


[1] http://www.postgresql.org/docs/8.3/static/nls-programmer.html


--
   Euler Taveira de Oliveira
   http://www.timbira.com/