Use parallel compression tools for tarballs when available

commit f7735c5b:

cerbero/package: Share code for creating android and dist tarballs
_create_tarball() does the same thing in both classes.

commit b25c61d2:

cerbero/package: Use lbzip2 for tarballs when available
Also, always use `tar` on platforms other than Windows. The tar
shipped with MSYS is very old and slow, but it's quite performant on
other platforms.

Speeds up packaging on my machine from 7m30s to 2m3s. The speed up is
even more drastic on the GitLab runners: 2m21s to 3.7s.

Closes https://gitlab.freedesktop.org/gstreamer/cerbero/issues/132

Closes #132 (closed)

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Android-Universal package times

All these stats are from my 4 year old laptop with an SSD. More stats on #132 (closed).

bzip2 -c config/cross-android-universal.cbc package -f:

real    7m15.595s
user    7m4.909s
sys     0m9.444s

lbzip2 -c config/cross-android-universal.cbc package -f:

real    2m8.267s
user    7m6.246s
sys     0m8.768s