new Simplified Chinese language & allow for a hyphenated ZH-CN language code

* ZH-CN (Simplified Chinese) is not 100% translated. The entire QoS page, long paragraphs of text & the menu system were skipped.
* some minor changes to accommodate a hyphenated lang code in the menu system + localizing

* add the favicon for the default theme. Its the corner of a frame with G that references the arc of the Gargoyle's wings. Support for favicon is already present via this commit https://github.com/ericpaulbishop/gargoyle/commit/21e9ea64751a245005423f61bbb7cf3b879237a9