Add Gitweb support for LZMA compressed snapshots

Hi,

I thought I would submit this little patch I made to my gitweb. I am  
on a relatively slow
connection, and so LZMA compression time is less of a  concern than  
bandwidth---I'm
guessing that I am not the only person who suffers from slow internet  
connection
syndrome.


--
Mark A Rada (ferrous26)
marada@uwaterloo.ca