Pull Changes from Git and prune local/

Migrating out Changes file to ChangesFromGit so I won't have to remember to update it manually. If people desperately need the old commit messages broken out by release I can go back and tag the releases based on the old changes file.

Additional to prevent myself from pulling a "perigrin" as rjbs put it, I've added a directive to prune Carton stile local/ directories.
test for more accpetable backends on install

We have added more acceptable backends (Cpanel::JSON::XS and JSON::PP) but we didn't update the tests during installation.
test without JSON::XS and add a compat note

JSON::XS 3.x is incompatible with JSON.pm < 2.90 in the exact way
that JSON::Any uses things in the test suite.

So we set the tests to ignore JSON::XS (using Test::Without::Module)
thanks to ether for suggesting it.

And we add a note about the situation to the POD so that others can
figure out what is going on.