[PATCH 1 of 2] keyword: expand RCS/CVS-like keywords in local directory

[Rafael Villar Burke]

What would probably be a nice feature is being able to expand keywords 
only when using hg archive with an --expand-keywords option. That way 
you don't mess with keyword expansion on normal operation, but you can 
get it when using archive, that I understand is hg's unversioned way to 
ease releasing the code.
Maybe it can also help hgweb to use it when downloading tarballs from it.

Good work,

Rafael Villar Burke