readme: what to do if configure fails
readme: tidy link to mps build from source
readme: document dependencies
readme: you can't send Accept-Encoding to an upstream
headers: strip accept-bytes and vary-accept-encoding

If we're proxying the origin server might advertise `Accept-Ranges: bytes` but
we don't support range requests.  So we need to remove the header.  We also need
to not add `Vary: Accept-Encoding` twice, and because the gzip encoding will add
it later we need to remove it here.
Merge pull request #132 from pagespeed/jefftk-strip-headers

headers: strip accept-bytes and vary-accept-encoding
readme: the Library command uses longer hashes now
readme: link to ngxpagespeed.com
resources: reject non-HEAD non-GET requests
config: interpret amd64, i686, and i386
Merge pull request #139 from pagespeed/jefftk-32bit-arch

config: interpret amd64, i686, and i386
generate-configuration: process ngx_system_test.sh results
Merge remote-tracking branch 'origin/master' into oschaaf-generate-config