Use gzip compression when contacting server.
Use deflate instead of gzip

This is based on some benchmarks:

~/tmp » ruby gzip_bench.rb
Original bytes: 14418
GZIP using Zlib::DEFAULT_COMPRESSION: 2804
  0.000000   0.000000   0.000000 (  0.000814)
GZIP using Zlib::BEST_SPEED: 3135
  0.000000   0.000000   0.000000 (  0.000223)
Deflate using Zlib::DEFAULT_COMPRESSION: 2792
  0.000000   0.000000   0.000000 (  0.000319)
Deflate using Zlib::BEST_SPEED: 3123
  0.000000   0.000000   0.000000 (  0.000199)

The deflate compression algorithm (which gzip uses) is widely available
across server-side technologies:

* http://golang.org/pkg/compress/flate/
* http://lua-users.org/wiki/ModuleCompressDeflateLua
* http://nodejs.org/api/zlib.html
* http://httpd.apache.org/docs/2.0/mod/mod_deflate.html

While nginx supports gzip/deflate for responses, it does not appear to
support either for input. :(