Overhaul of Settings

The settings system has been overhauled, made standalone, and more
accessible to plugins.
Merge https://github.com/Radnen/spherestudio
Fix x86/x64 build config

Not all projects were being built unless AnyCPU platform was selected.
Build config modified to solve this, and also removed AnyCPU platform
since this requires all dependent DLLs to be built with AnyCPU (i.e.
pure .NET)