[STORM-68b] Default permissions floater overhaul

Adds separated default permissions for Objects, Uploads, Scripts, Notecards, Gestures and Wearables.

Compatible with Export Permission
Backwards compatible with default permissions for objects on regions where AgentPreferences capability is not available (opensim users rejoice!)

These changes to llfloaterperms are made available under lgpl, if there's a v3 that wants to adopt default export permission for opensim.
Confirmation for removing users, also reposition the remove button icon
Fix any and all crashes relating to initialization of UI components that may need the name cache to be initialized already.