Move tests from t to xt

pod tests should never be run by an end user (especially the failing
ones) and letting end users try to create/drop test databases is a
recipe for failure (especially if run from the cpan client).

Write up docs on how to run tests in case you're developing.
Add INSTALLATION instructions

This contains the work-in-progress 4.2 instructions.
Also bumps our copyright.
Minimal docs to pass tests
Update CHANGES for a new release