godashboard: bz2 compress logs in data store
godashboard: bz2 compress logs in data store

This results in a 10-20x size reduction per record.
(from ~150kb to ~10kb)

This revision has been pushed live, as I'm in the process of
converting Log records to bz2-compresed CompressedLog records.
I would have waited but we're running seriously low on space
and it seemed like a sane (and reversible) move.

R=rsc
CC=golang-dev
http://codereview.appspot.com/872048

d0f/go-zh,rdp/rogerpack2005-golang,npe9/noahevans-go9,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,rdp/rogerpack2005-golang,scirelli/scirelli-go,npe9/noahevans-go9,sanjosh/sanjos100-tipc,webfd/go-zh,scirelli/scirelli-go,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,d0f/go-zh,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,npe9/noahevans-go9,rdp/rogerpack2005-golang,Triskite/willstone-goclone,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,mhennings/marcohennings-go,scirelli/scirelli-go,d0f/go-zh,sanjosh/sanjos100-tipc,Triskite/willstone-goclone,bryanxu/go-zh,npe9/noahevans-go9,sanjosh/sanjos100-tipc,Triskite/willstone-goclone,mhennings/marcohennings-go,bryanxu/go-zh,rdp/rogerpack2005-golang,glycerine/jeaten-go-arrayof-structof,Triskite/willstone-goclone,Triskite/willstone-goclone,mhennings/marcohennings-go,scirelli/scirelli-go,bryanxu/go-zh,npe9/noahevans-go9,rflanagan/reginaldflanagan-project1,Triskite/willstone-goclone,webfd/go-zh,npe9/noahevans-go9,mhennings/marcohennings-go,webfd/go-zh,rflanagan/reginaldflanagan-project1,d0f/go-zh,mhennings/marcohennings-go,webfd/go-zh,bryanxu/go-zh,webfd/go-zh,bryanxu/go-zh,npe9/noahevans-go9,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,Triskite/willstone-goclone,bryanxu/go-zh,rdp/rogerpack2005-golang,glycerine/jeaten-go-arrayof-structof,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,webfd/go-zh,Triskite/willstone-goclone,bryanxu/go-zh,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,scirelli/scirelli-go,webfd/go-zh,bryanxu/go-zh,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,rflanagan/reginaldflanagan-project1,rdp/rogerpack2005-golang,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,d0f/go-zh,scirelli/scirelli-go,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,npe9/noahevans-go9,d0f/go-zh