debian/source.filter: more files to ignore

Debian added more testing stuff for unit tests, there is mostly no source
from the JS files, but also don't need them.
debian/gbp.conf: adopting changes for Debian experimental branch
Imported Upstream version 28.0~b1
Merge tag 'upstream/28.0_b1' into experimental

Upstream version 28.0~b1
rebuild patch queue from patch-queue branch

obsolete patches (fixed upstream):
debian-hacks/Do-build-time-detection-of-2-bytes-wchar_t-and-char1.patch
debian-hacks/Fix-build-failure-for-header.py-and-typelib.py.patch
debian/control: add libpulse-dev build dependency

New Thunderbird version needs now a build dependency on libpulse-dev.
debian/control: bumping some version of build dependencies

The packages nspr4-dev, sqlite-dev and libvpx-dev needs at least to be
present in a higher versions.
debian/icedove-dev.install: adopt upstream changes

Mozilla has changed the old directory order and release of files in
there. Remove no longer shipped files and changed source of remaining
files.
remove file temporary