Adds datestamp and changelog
Adds datestamp and changelog

- Adds datestamp to revision to get proper ordering per Fedora [Packaging Guidelines](https://fedoraproject.org/wiki/Packaging:Versioning)
- Adds note to set static values before creating an SRPM. This fixes and issue that if you
  package an SRPM today and then you compile it tomorrow, the commit and datestamp
  may be incorrect.
- Adds changelog
- Other cleanup noted in Changelog
google/stenographer,gconnell/stenographer,google/stenographer,google/stenographer,gconnell/stenographer,gconnell/stenographer