Instead of "send feedback", "send app feedback".

* This is more consistent with Android.
* Hopefully it would help in avoidance of off-topic feedback, too.

Change-Id: I2301999e10fe8dc1db6f67822fd0f7c6f4344f73
Merge "Instead of "send feedback", "send app feedback"."
Footer updates

* update to match new design
* 'last modified' bit shows green if mod <1day
* new language text/layout
* wikifont glyph icons
* tiny license footer
* some basic RTL flipping
* last-mod is clickable

Todo in followups:
* fix last-mod timezone bug
* make last-mod either show on web or have a 'see the rest on web' clickable
* plural fixes for timestamps, language count

Change-Id: Ic69804ac687e36757d5ddc5c86a0d4a3155c77ff
Merge "Footer updates"