fix gh_pages push skip

So you may have noticed that the nightly batlab runs stopped pushing nightly documentation builds at some point in the last few weeks, without any changes to Ciclus.  As far as I can tell, batlab has stopped accepting platform specific platform_post options, which is where our pushing to github actually takes place. Since this is almost certainly an issue with batlab, I've emailed them, but since I don't know how long that is going to take I've also updated the scripts to work without this step.  Some of the middle commits also include attempts to keep batlab from pushing if there is no change in the documentation, but that is going to require a bit more work and I didn't want to hold this up any longer.

See 
http://submit-1.batlab.org/nmi/results/details?runID=211532
https://github.com/cyclus/cyclus/tree/gh-pages
https://github.com/cyclus/cycamore/tree/gh-pages