Added filter groups to speed up "is:" and "ext:"

Adds an Ack::Filter::Collection class that can contain filters and
internally sort them into groups. The groups can then be optimized
for faster filtering.

Currently "is" and "ext" filters are grouped and replaced by a fast
hash lookup. This leads to improved performance when many such filters
are active, like when using the --known command line option.
Add perlcritic author test
Ignore perlcritic test history
Add Perl::Critic deps to travis
Don't run tests for Perl::Critic

There's a test failure in the most recent release of Perl::Critic (1.118)
if you're using the latest version of Config::Tiny (2.17).  We will
avoid Perl::Critic tests until this is fixed.
Don't run tests when installing any Perl::Critic stuff

Apparently just ignoring tests for Perl::Critic wasn't good enough;
installing the other Perl::Critic stuff tries to re-install
Perl::Critic.
Properly install Perl::Critic without tests on Travis

I didn't realize I was using --installdeps; this should fix
the Travis build for the Perl::Critic stuff
releasing 2.09_01
for testing
prepped for work on 2.09_01
note about 2.06
Ignore file .timings.json
Add --color option to timings script

Setting the --color option causes the timings script to
color the timings based on whether they were faster or slower than
the previous ack tested.  Right now it's a simple faster/slower
distinction, but in the future we could take advantage of larger
colorsets that more modern terminals provide if we want.
Add --times option to timing script

This option allows a user to run the acks several times over to
try and get a more accurate measurement
Start on ack developer's guide
Updates to the developer guide
Added missing return to Ack::Filter::Is::to_string
Start of log about how to cut a release
note about 2.1 vs 2.10
Add "But I can't contribute" section to DEVELOPERS

This section is intended to educate users on ways they
can help with ack