Blender Git Loki

Cleanup: BLO_read: linking API arg order and name.

linking API funcs would use 'name, idcode', when all other code here uses
(more sensible) 'idcode, name'.

Also, use 'name' arg name when we expect a bare name, without the prepended ID code, and
'idname' arg name when we expect a complete ID name.

And here too, idcode shall be short, not int!