Don't place Mobile appendix in the Assets folder

[Kleptine]

After mobile builds, I get a large folder of build information in my assets folder this has a few consequences:

• Requires an asset database refresh after build.
• Extends project import time (a small amount, but import times are a 'death by 1000 cuts' situation)
• Requires .gitignore, etc.

It seems these would make much more sense to be placed in the Library/.