Update to 23.0.1

Changelog:
 FIXED
23.0.1 - Rendering glitches on H.264 video only in FF23 on Vista (901944)
FIXED
23.0.1 - Spellchecking broken with non-ASCII characters in profile path (902532)
FIXED
23.0.1 - Audio static/"burble"/breakup in Firefox to Firefox WebRTC calls (901527)
Updated www/firefox to 23.0.1
Update "youtube-dl" package to version 20130817. A changelog is not
available as usual but it fixes video downloads from Youtube for me.
Note update of the "youtube-dl" package to version 20130817.