iceowl-extension: replace skin and icon dir with symlink
document changes and release 31.0-2
icedove.postinst: remove obsolete symlink handling

follow up for 892c39cfbc964b03b014f5ef510cbc6366c965db
debian/gbp.conf: adopting experimental branch
Imported Upstream version 32.0~b1
Merge tag 'upstream/32.0_b1' into debian/experimental

Upstream version 32.0~b1

Conflicts:
	mozilla/addon-sdk/source/.gitattributes
rebuild patch queue from patch-queue branch

modified patches:
icedove/fix-branding-in-migration-wizard-and-the-addon-manag.patch
debian-hacks/remove-non-free-W3C-icon-valid.png.patch

obsolete patches (fixed upstream):
porting-armel/fix-skia-for-ARMv4.patch