Provide improved flow for selling objects in world

Presently, one can set an object for sale in either the build/edit floater or the Object Profile panel. Both of these have the same controls, and share the problem in STORM-1453: that the item is for sale as soon as you check the For Sale box, which is before you have a chance to set the terms of sale (whether you're selling a Copy, the Contents, or the Original, and the price). They also both have the problem in VWR-24118 - setting the item for sale modifies the default Touch behavior of the object itself, which may or may not be what the user intended.

This issue tracks a project to replace the set of sales-related fields in both of the object floaters with just a 'Sell Object' button, which would then bring up a wizard-style dialog similar to the land sales floater that gives you a sequence of decisions to make:

1. Selling Price
2. Sale mode (Copy, Content, Original)
3. Whether or not Touch is modified to the default Buy action (my personal feeling is that this should be the default only when the previous choice is Content - anything else ends up with the new owner having an object whose default touch is Buy, which they sometimes won't be allowed to sell)
4. Confirm the next-owner permissions

The dialog would have a Cancel button and Sell button at the bottom, which would either discard or commit all of the above.