obj export that includes object names

[rrockafellow]

update the obj exporter to include the name of the object. currently only the material name is associated with each object exported.
The name is currently getting lumped into the use material name.  This also means that  name of the material can stop having the object named added to it.

The obj export is currently missing this line for

g 'name of object goes here'

In the .obj file it would like this:

f -9/-9/-9 -6/-6/-6 -8/-8/-8
f -5/-5/-5 -6/-6/-6 -9/-9/-9
f -10/-10/-10 -8/-8/-8 -1/-1/-1
g Partb
usemtl color:163:163:169
v 23.2055 -2.268 -2.49434
v 23.4375 -2.268 -3.65903
v 23.4375 -2.268 -2.49434

*Also as a bonus if the object names could be checked  and updated to make sure that the are unique would be perfect.