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
* Use expression bodies in Emulation.Cores, and a few other misc cleanups
* remove unused usings in Emulation.Common
* cleanups in Tables_Direct.cs
* some cleanups in nes boards - redundant code
* remove some redundant array initializers in Emulation.Cores
* cleanup AmstradCPC.Controllers
* use object initializers in a lot of places
* nes mappers - remove disch's notes comments in favor of the nesdev wiki link
* cleanup CdtConverter.cs, mostly use of object initializers
* remove redundant .ToString() calls in Emulation.Cores
* using var in Emulation.Cores
* AmstradCPC/ZXSpectrum - simplify some linq, tabs instead of spaces, a few other misc cleanups
* Use null-propagation in Emulation.Cores
YoshiRulz