Fix missing "Send to OptionTree" button in CPT

When a Custom Post Type does not support the "editor" then the "Send to
OptionTree" button is missing from the "Media Library" tab in the upload
iframe. This fixes it by adding the button if it is missing.
Merge pull request #115 from jomaddim/wip

Fix missing "Send to OptionTree" button in Custom Post Types with no "editor"