LICENSING: change topmost LICENSE (and COPYING) to MPLv2
LICENSING: unify CC0 Public Domain dedications
LICENSING: clarify GNU LGPLv2+ license for GLib/Gtk+ based code
LICENSING: clarify XFree86 License 1.0 for X.Org based code

* Licenses were clarified according to:
  http://www.x.org/releases/X11R7.7/doc/xorg-docs/License.html
LICENSING: regionimpl.c: put Rapicorn additions under MPLv2
LICENSING: use MPLv2 license for aidacc source code
LICENSING: use MPLv2 license for all original source code
LICENSING: document project licensing under MPLv2
Merge branch 'MPLv2'

* MPLv2:
  LICENSING: document project licensing under MPLv2
  LICENSING: use MPLv2 license for all original source code
  LICENSING: use MPLv2 license for aidacc source code
  LICENSING: regionimpl.c: put Rapicorn additions under MPLv2
  LICENSING: clarify XFree86 License 1.0 for X.Org based code
  LICENSING: clarify GNU LGPLv2+ license for GLib/Gtk+ based code
  LICENSING: unify CC0 Public Domain dedications
  LICENSING: change topmost LICENSE (and COPYING) to MPLv2