import_obj - comments, docstring additions, cleanup.
OBJ export: -renamed export_obj
faster edge exporting (use edges LOOSE flag rather then finding zero face user edges)
check for file before overwriting
use object iterators
http://mediawiki.blender.org/index.php/ScriptDev/Guidelines
* Recursive search was enabled by default, if your OBJ happened to be at root path, loading the OBJ could take ages. Made recursive searching optional.
* MAX's MTL exporter replaces spaces with underscores, image loading checks for this and loads the name with spaces if the one with underscores dosnt exist. not realy a problem with the importer but annoying to manually replace lots of images.
The original obj importer was ok but it gradually got slower
as it had to support quirks of rare files.
This importer supports these quirks without bad workarounds and ~250 less lines.
* Moved from NMesh to Mesh
* Import smooth groups as hard edges
* Import Lines from sketchup (Thanks Wavk)
* Uses less memory
* faster (On a 70meg poser test model, benchmarked from 130sec to 41.2sec)
Not yet supported from the old importer-
* Scaling down to a bounding area
* Importing multiple obj's at once
* Using existing materials in the .blend
* Importing as a group instance.
