use "graceful" instead of "reload" for Apache

The "reload" command is actually HUP which interrupts worker processes
in the middle of serving requests, whereas we actually want "graceful"
(USR1) which allows outstanding requests to finish.

http://httpd.apache.org/docs/2.2/stopping.html

Change-Id: I9fd6cfcffc06830a8c98289b6ba78fe603aae481
Do not stringify power password if it is None

Bug: 1054616
Change-Id: I881f1ef292f763a2fd898edf581ceb4d97de9457
Merge branch 'release-0.14' into release-0.15

No further maintenance releases of 0.14 are currently planned,
but some additional updates have been implemented on that branch
to ensure they're included in a 0.14.5 release if we later
decide one would be appropriate.

Bug: 1054616