Revert "Fixed Issue with BBcodes not Rending"

This reverts commit 3d2c1777ba75df9d5e9c58efc41038bb0e92b9cd.
This commit was accidentally included when I pulled #166 when I
meant #167.
Set the standard JSON content type for a wider compatibility

Since the "application/json" type is the default one used in CakePHP core and accepted in a RFC4627
Taxonomy: Lost Comment settings when editing Types