Make sure that blank swf is loaded if fallback document conversion does not work.

Fix poll options remain visible on html5, closes #3806 HTML5

Fixed user leave problem on private chat, close #3799 HTML5

HTML5: Switch to icons v11, update some icons in the client, minor UI touches

HTML5: Fix missing import causing breakouts to not work

 user internal userId instead of external userId 

Delete the initially converted swf to be sure that if fallback convertion does not work we get the blank swf loaded.

Fix user drop down - HTML5 Issue #3764

Fix multiple welcome messages, issue #3792 HTML5

 Check userId when validating token

Display WebRTC stats inside the Flex client

 - check if the client validating the token mathes the userId of the registered user. If
   we don't, the client can pass any token and impersonate other users.

[HTML5] Fix client freeze on private chat partner leaving. Fix for #3786

Show message "Recommend using either Firefox or Chrome for better audio" in audio window

 Cleanup