Add getter & setter for translatable_content in CMSPlugin
Typo
Added tests for get/set_translatable_content
cosmetic changes for @piquadrat
wording changes in comments
Removed uneccessary utf-8 encode
Removed get_plugin_instance in getter/setter

If you're not calling these methods from the instance you're likely to use the CMSPlugin's methods instead of the ones of your plugin
fixed logic
Code cleanup
Added docs
Merge pull request #2478 from Chive/develop

Add getter & setter for translatable_content in CMSPlugin