Version Note field is shown based on com_content settings for all extensions

### Issue
The "Version Note" field for the content versioning is shown in each extension regardless of the component settings.

### Bug description
This is due to a bug in the joomla.edit.global JLayout file which checks the component parameters based on the `extension` instead of the `option`.

### Proposed Fix
The PR will fix this by first checking for the option, and if this is 'com_categories' it will look up the extension instead and take only the first part of it (because the second may be a section, like "com_content.other").

### Testing
1. Enable Version History in com_content
2. Diable Version History in com_contact
3. Edit a contact and see that the "Version Note" field still shows.
4. Disable Version History in com_content
5. "Version Note" is no longer shown
6. Enable Version History in com_contact
7. "Version Note" still doesn't show.
8. Apply patch and make sure everything works now as expected (including categories).

#### Tracker
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=32889