Bug 387678: Warnings thrown when running ./runtests -v 11 - Patch by FrÃdÃric Buclin <LpSolit@gmail.com> r=dkl a=LpSolit

Bug 376908: Installation process should not assume skins are in the same directory as checksetup.pl - Patch by guillomovitch@zarb.org r/a=mkanat

Patch by Marc Schumann <wurblzap@gmail.com>;
r=myk,mkanat; a=myk