blender addons: clean up indentation and typo.
blender addons: refine interface
blender addons: cleaning the temporary scene filename
blender addons: fix typo in addon info location.
blender addons: activate addon preferences.
blender addons: use cgru_location variable in the addons.

Because if the addon is install in the user default script
location, we need to provide some environment variable to the
script otherwise addon fail to send the job.
blender addons: cleanup variables name
Save temp blend file but stay in the main file.
blender addons: split render layers in block implementation.
I'm not really happy with this because of redundancy in the code.
blender plugin: enable automatic python script execution
blender plugin: forget from previous commit
Remove code copying
Small fix if Layers>1
Added description fo ### things.
blender plugin: 'images' variable was not use when split render layer
enable
blender plugin: correct previous commit
blender plugin: replace strings substitution with regex
blender plugin: refactoring

 - move CGRU env variables checks before doing anything
 - less broad exception clause
 - using .format for command line and other string concatenation
 - set block.setFiles correctly
 - rename variables names
 - remove some unused fonction and variables
 - reformating code (pep 8 but without tabs as spaces :)
blender_plugin: set setWorkingDirectory correctly
blender plugin: check if a layer is use or not