Pull in websockify 4725aa7.

- Update to c0855c6cae of web-socket-js

- Update both the submodule and the swf build. The submodule now
  contains the unobfuscated source for swfobject.js which should make
  websockify more DFSG compliant.

- Remove Hixie support. iOS 6 now includes HyBi support which means
  there is no remaining platform that needs Hixie.