Add support for upstream_cfg_prepend

Makes things possible like specifying ip_hash and/or keepalive.
Merge pull request #47 from oxilion/upstream_cfg_prepend

Add support for upstream_cfg_prepend
Changed SSL ciphers to the recent default for Nginx which is much
    more secure
Added SSL caching to speed up SSL requests
Add server_tokens to the global config so this can be turned on|off
    between dev and prod
Add proxy_set_header to vhost as different vhosts may require different
    headers and the global setting is not ideal
Minor space formatting so that the generated files are fractionally
    more readable
Changed param defaults for Microcosm
Added support for SPDY now that nginx 1.4 has arrived
Added back RC4 to mitigate BEAST attacks
Added OCSP SSL stapling to reduce SSL handshake by 30% by sparing the revocation list if the certificate includes the intermediate layer to identify the trusted source
Fixed ssl_stapling instruction
Merge pull request #48 from microcosm-cc/master

SSL improvements (default ciphers & caching), server_tokens option, and proxy_set_headers for vhosts
saner defaults