Drop support for Mento

It seems that Mento is end.
http://www.mento.info/
http://blog.mento.info/
Drop support for PingFm

Ping.fm is end.
http://ping.fm/
http://blog.seesmic.com/ping-fm-and-seesmic-ping.html
Update Digg ICON

* Add digg.ico

via http://digg.com/favicon.ico
Update Gyazo ICON
Update Readability ICON

* Add readability.png

via http://cdn.readability.com/e2bbf4/images/favicon.png
Update Faves ICON

* Add faves.ico

via http://fave.net/favicon.ico
Move Snipshot icon from data URL to favicon
Drop support for LivedoorClip

livedoor Clip is end.
http://clip.livedoor.com/
http://blog.livedoor.jp/staff_clip/archives/52265344.html
http://blog.livedoor.jp/staff_clip/archives/52280240.html
Drop support for Wassr

Wassr is end.
http://wassr.jp/
Remove GazoPa Model

GazoPa is end.
http://www.gazopa.com/

It seems that GazoPa Model isn't used.
Drop support for Clipp

clipp is end.
http://clipp.in/
v0.0.2

* Drop support for Mento, PingFm, LivedoorClip, Wassr, Clipp, because of service end
* Fix Hatena Bookmark big icon bug
* Update some Models icon