Remove bzip2.

(probably added because I did not know how to work with the feeds)
poppler: upgrade to version 0.24.1
cups-filters: upgrade to 1.0.37 (requires upgrades to glib2 and libffi, which I took from Barrier Breaker)

Ghostscript: do not install filters as Openprinting's cups-filters is
now the new upstream of these.
Readme update
Fix #6 remove libjpeg-turbo
lcm2: upgrade to 2.5