Fix dates from RPM SPEC changelog

`make rpm` gives these warnings:
  warning: bogus date in %changelog: Thu Feb 28 2014 Michael DeHaan <michael.dehaan@g.c> - 1.5-0
  warning: bogus date in %changelog: Thu Jul 05 2013 Michael DeHaan <michael.dehaan@g.c> - 1.2-2
  warning: bogus date in %changelog: Thu Aug 6 2012 Michael DeHaan <michael.dehaan@g.c> - 0.7-0

  RPM build errors:
      bogus date in %changelog: Thu Feb 28 2014 Michael DeHaan <michael.dehaan@g.c> - 1.5-0
      bogus date in %changelog: Thu Jul 05 2013 Michael DeHaan <michael.dehaan@g.c> - 1.2-2
      bogus date in %changelog: Thu Aug 6 2012 Michael DeHaan <michael.dehaan@g.c> - 0.7-0