druid: account for Glyph of Sprouting Mushroom

fixes gh-128
Merge pull request #135 from Rainrider/druid

druid: account for Glyph of Sprouting Mushroom
Druid: added a custom rule for Germination, showing both Rejuvenation and Germination.

Fixes GH-133.
Merge branch 'master' of github.com:Adirelle/AdiButtonAuras

Conflicts:
	rules/Druid.lua
Gives the overlays an explicit size.

Should fix GH-139.
Masque support: the option now simple enables/disables the group, instead of (un)registering the buttons.