Investigate if we can improve zlib speed

[puzrin]

(*) Probably, that can be moved to separate library.

Currently we use deflate from Imaya's zlib.js, but it seems that speed can be improved. Note, we need deflate with headers (see zlib spec), not raw deflate. Alternate ports to investigate:

• https://github.com/gildas-lormeau/zip.js/tree/master/WebContent - fastest, needs small change to to support Arrays too (now requires Uint8Array)
• http://www.onicos.com/staff/iz/amuse/javascript/expert/
• https://github.com/dankogai/js-deflate

Keep in mind, that all libs are ports of outdated zlib code. Need refresh.

[puzrin]

Replaced with (1). Compression speed boosted ~2.5x times.