Blender Git Loki

Add compatibility for older Collada files

The Fix in 273 creates a backward incompatibility:
Collada files that have been created with an older Blender version
will contain the spotlight_size in Radians where Collada wants
this value to be in DEGREE.

This fix adds a check for the Blender Version that was used to create the
Collada file. If the Collada file was made by an older version of Blender
then the importer will assume that spotlight_size is specified in RADIANS.

Reviewers: campbellbarton, sauraedron

Reviewed By: sauraedron

CC: jesterking

Differential Revision: https://developer.blender.org/D279