Preindex static resourcing

preindexing now will call new management command which does all the static resourcing.
however, the output will be now saved to a file AND a cache based upon the current git sha commit.

when deploying the command will check the cache first, or regenerate on its own if the cache somehow disappears.

the resource versions also use greenlets to multi-call all the commands (using a git-dir call instead of cd'ing) - results inconclusive on local SSD dev though.