Add classic USE flag to gnome meta

This USE flag brings in gnome-shell-extensions that simulate a classic
GNOME 2.x feel.
Remove 3.10.0 ebuilds that have 3.10.1 available

A bit of cleanup for stuff that is up to 3.10.1 we don't need to keep
the 3.10.0 ebuild around.
Add missing gstreamer plugin deps to cheese

Fixes Heather/gentoo-gnome #43
readme+=layman
Update README.md
x11-libs/gtk+: Fix glib and cairo dep versions, close GitHub issue #44
Merge remote-tracking branch 'upstream/master'

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