More ergonomic script selection

[Felk]

Right now, selecting a script from the GUI is a bit painful, because you have to navigate to the python file each time. This should be more ergonomic. A few ideas:

• Remember the previous location the user navigated to
• Offer a list of recently used scripts
• Have a fixed directory for scripts (similar to where you'd put shaders for examples) and select scripts from there

this is something THC98 requested on the tasvideos forum: http://tasvideos.org/forum/viewtopic.php?t=22105