Trebuchet : Add folder on folder checks

- Check if the new folder can accomodate all items
- Don't expand folder if trying to drop folder on folder

Change-Id: I208e3afd4ee6aeeea01928fc77e136d6085c4fdc
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Trebuchet into kk