Teach mod_image_for_test to disable idle-suspend features.
Teach mod_image_for_test to disable idle-suspend features.

This prevents the machine from suspending while it is being tested.

TEST=Modified an image for test and verified that powerd did not suspend.
BUG=chromium-os:3694

Review URL: http://codereview.chromium.org/2620008

vmware/coreos-scripts,crawford/scripts,trnubo/scripts,sigma/coreos-scripts,sigma/coreos-scripts,crawford/scripts,bcwaldon/coreos-scripts,zhang0137/scripts,coreos/scripts,smilart/scripts,mischief/scripts,BugRoger/scripts,trnubo/scripts,andrejro/coreos--scripts,BugRoger/scripts,vmware/coreos-scripts,vmware/coreos-scripts,fivethreeo/scripts,endocode/scripts,nicescale/scripts,gtank/scripts,mjg59/scripts,mjg59/scripts,nicescale/scripts,endocode/scripts,mjg59/scripts,andrejro/coreos--scripts,sigma/coreos-scripts,smilart/scripts,fivethreeo/scripts,crawford/scripts,gtank/scripts,marineam/coreos-scripts,smilart/scripts,marineam/coreos-scripts,mischief/scripts,marineam/coreos-scripts,andrejro/coreos--scripts,bcwaldon/coreos-scripts,glevand/coreos--scripts,zhang0137/scripts,trnubo/scripts,glevand/coreos--scripts,mischief/scripts,BugRoger/scripts,fivethreeo/scripts,zhang0137/scripts,nicescale/scripts,coreos/scripts,bcwaldon/coreos-scripts,endocode/scripts,gtank/scripts