Categorize the entity properties and mark them as hidden/uneditable as needed

[Sage-of-Mirrors]

The templates that define the auto-generated properties in the entity templates must be categorized. Currently, all properties without an explicit category name are marked as belonging to a "Misc." category. Most of the categories will probably be "

Properties in these templates can also be marked as Hidden - demoting them from properties to private fields - and Editable, allowing them to be edited by the user.

• Most values should be made editable by the user.
• Certain types of properties - such as indices and offsets - should be marked as Hidden.