Add CHANGES.rst file

This took longer than I expected it would... there were a lot of changes since the 1.0 release.

I originally wanted to link to both issues and pull requests as well as thank bug identifiers and fixers.  I didn't spend the time to retroactively identify all of these issues and people.

I did link a relevant pull request to every change noted except for one (Lithuanian phone number fields which were added in fc09fa0dbb311d1d1b65c131bc5bc25a6526b42c).