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