* Rename ButtonSchema to PadSchemaControl, create ButtonSchema subclass, rename
AnalogSchema to AnalogStickSchema, and make PadSchemaControl abstract
* Replace switching on PadSchemaControl.Type (enum PadInputType) with type
checks
* Refactor and merge VirtualpadTool.CheckPads() into .CreatePads() (it was
easier than just using type checks in the old algorithm)
* Move members from PadSchemaControl to subtypes and cleanup
effectively resolves#1200
* Replaced floats in FloatRange with ints (would have used shorts but
SubGBHawk/SubNesHawk use an axis to hack in cycle count or something), added
both Range<int> and Range<float> auto-properties
* Added bool field IsReversed to FloatRange
* Added enum AxisPairOrientation and factory method using it
* Cleaned up usages of FloatRange fields and properties
* Added new properties to PadSchema.ButtonSchema for type
PadInputType.AnalogStick (to hold the two FloatRanges) and used
ControllerDefinitions from cores to dedup these ranges in the schemata
* Made VirtualPadAnalogStick work properly: both the direction and bounds are
correctly set from the controller schemata, the polar conversion measures angles
consistently (though I think it might not work outside -128..127 e.g. for PSX),
and I didn't break the sensitivity override, plus negative percentages might
work now but I didn't allow those
* Renamed FloatRange to AxisRange, but did not rename related symbols
YoshiRulz