fixed crash on auto export of blinn materials
closed #19
implemented render layers in edft
auto translated surface shaders now have constant surface shaders not physical
implemented transparency auto translation for generic materials
plumbed in max ray intensity controll
killed idiotic bug to do with copy and paste, i apologise and promise to mend my ways
removed un necessary check
minor formatting change
re implemented progress window
added ability to cancel scene export
Merge pull request #131 from jonathantopf/master

miscellaneous fixes, support for render layers, max ray intensity, added progress bar and ability to cancel export