YaHTTP upstream update

Fixes:
  - Chunked responses and requests are parsed properly even when
    the headers and body come in separately.
list make install content
don't build .a files for backends, we do not use them at all
make lmdbbackend use libtool object
remove .la files during make install
Merge pull request #1495 from cmouse/yahttp-update-20140630

YaHTTP upstream update