Added a setting for CKEditor that disables the ACF

Added a setting for CKEditor that disables the Advanced Content Filter.
Merge pull request #196 from ramonakira/patch-1

Added a setting for CKEditor that disables the ACF
Added configuration variables for CKEditor 

Using these configuration variables we can now configure almost every setting of CKEditor.
Update docs with CKEditor config explanation

Update advanced-usage.rst with explanation about CKEditor configuration settings
Update advanced-usage.rst

Forgot a critical piece of information
Merge pull request #197 from ramonakira/patch-2

Added configuration variables for CKEditor
Merge pull request #198 from ramonakira/patch-3

Update documentation with available CKEditor config settings
Merge branch 'master' into dev
'un-cherry-picked' changes to advanced usage that were only in dev