Add batch plotting code for iterations plots

Still need to test this on Minerva and add threshold plotting functionality
Handle case where no results are found
Header line is now skipped in results files
Clean up plots a little
use pyplot.plot instead of pyplot.errorbar
Use ymax instead of ymin

Need more coffee...
let mpl choose legend location
Add initial threshold plotting code

Still needs testing on Minerva
Fix indent
Add missing import
use linestyle instead of marker
Add more stringent checking of dirs to process

Could hit a case where .tmp dirs were being processed, which we never want to happen.
Merge pull request #32 from jrrideout/issue-15

Added batch processing script to generate plots