Parts of a test to drive the long-running content filter interface
has been split into its own module, hopefully to eventually become
reusable.
* cc/git-packet-pm:
Git/Packet.pm: extract parts of t0021/rot13-filter.pl for reuse
t0021/rot13-filter: add capability functions
t0021/rot13-filter: refactor checking final lf
t0021/rot13-filter: add packet_initialize()
t0021/rot13-filter: improve error message
t0021/rot13-filter: improve 'if .. elsif .. else' style
t0021/rot13-filter: refactor packet reading functions
t0021/rot13-filter: fix list comparison