K 10
svn:author
V 6
emaste
K 8
svn:date
V 27
2015-12-03T12:17:09.120357Z
K 7
svn:log
V 560
newvers: Honour SOURCE_DATE_EPOCH as a build reproducibility measure

One reason the kernel does not build reproducibly is that it includes
a timestamp in the version string. SOURCE_DATE_EPOCH provides a standard
method to address this: it should be set to the last modification time
of the source, and build processes use the specified timestamp instead
of the "current" date and time.

This change uses SOURCE_DATE_EPOCH if it is set; how it gets set needs
to be addressed elsewhere.

Reviewed by:	bapt
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation

END