This commit removes local copies of websockify.
Instead `utils/launch.sh` performs the following logic:
If `utils/websockify` exists, use `utils/websockify/run` (if the latter
does not exist, or is not executable, fail, since this is probably a
mistake).
Otherwise, check to see if websockify is installed somewhere (try
`which websockify`). If it is, use that. Otherwise, clone
websockify from github, and tell git to ignore that directory.
Packaged versions of noVNC should simply list websockify as a
requirement. The debian packaging has been updated to reflect
this.
Closes#433
唐飞雄 (twitter: @tangfx)