Campbell please check/beautify if you like, but it works properly on OS X, either
opening Preview with the 'open' command or Photoshop, when the path is set
in user preferences.
unrelated changes that ended up being more trouble to commit separate...
- removed BLI_split_dirfile(), was nasty, occasionaly modifying the source string, it could create directories and used the $CWD in some cases. was only used in 2 places in filesel.c, if this gives problems can address without bringing back this function.
renamed BLI_split_dirfile_basic --> BLI_split_dirfile
- view3d_operator_needs_opengl was being called for offscreen render when it wasnt needed.
image.py has a function image_editor_guess(), please test on windows and mac. (using 'startfile' and 'open')
this is only used when the image editor is not set.
rename image.save() --> image.save_render() because it uses render settings for saving.
added image.save() which is like pressing save in the image view, saving to the images path and removing the dirty flag.
Running scripts directly didnt call the register function, even though this is not essential its good to be able to run a script directly and see changes in the UI.
