Frame selection for click-castings

[leaKsi]

Closed because I don't have enough free time right now to fix conflicts. I'm sorry! Feel free to re-open this.

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This PR:

• Adds frame selection for click-castings.
• Completely refactors cascading menu to support more than just buttons, and fixes sub-menus.
• Changes how click-castings are stored in DB.

I'm open for any suggestions about visuals.

Some images

   

Tested in:

• Retail
• SoD
• Cata

[enderneko]

Thanks for the great enhancement! will merge it after refactor the layout system. maybe this weekend.