Add 2 arguments to websockify.WSRequestHandler

This patch adds 2 arguments to websockify.WSRequestHandler for security:

* file_only: returns 404 response if non-file contents are requested.
             Required to disable directory listing.

* no_parent: returns 403 response if contents out of the web root are
             requested. Required to disable directory traversal.
Merge pull request #84 from nttdatainc-openstackers/master

Fix for issue #83
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.
Use upstream einaros/ws 0.4.27 with sub-protocol support.

Also, some connection error handling.
Add package file for websockify.js
Move javascript websockify files to other/js
Update to version 0.5.1

*** NOTE ***

This version of websockify no longer supports the old Hixie protocol.
Merge remote-tracking branch 'upstream/master'