Blender Git Loki

More "data types" for the Operator property system.

Now you can set/get: float, arrays (int and float) and string.

The only special function is OP_get_string, it is special
because return a pointer to the IDProperty data, so you can't
change/resize/free the string.

It's possible "fix" this with:
1) Return a "const char"
2) Return a duplicate string

All this new function are not in use yet, but i make a simple test
with the "move areas" operator (add a property of every type and then
print the result in the other size) and work fine, more test are welcome.

Other thing to check is the new OP_free_property function, because this
properties are only local to the operator, i choice free all this in the
"exit callback" of every operator (only move areas have property now),
so comment about this are welcome too :)

Also add some notes to the WM_api.h file.