Remove various never called internal setters from GlobalParams.h

TextKeepTinyChars: false, simplify if in TextOutputDev
DisableFreeTypeHinting: didn't actually have a getter :D
StrokeAdjust: true, adjust the code in Cairo/SplashOutputDev to use gTrue
ScreenType: unset, simplify switch in SplashOutputDev
ScreenSize: -1, simplify code in SplashOutputDev
ScreenDotRadius: -1, simplify code in SplashOutputDev
ScreenGamma: 1.0, simplify code in SplashOutputDev
ScreenBlackThreshold: 0.0, simplify code in SplashOutputDev
ScreenWhiteThreshold: 1.0, simplify code in SplashOutputDev
MinLineWidth: 0.0, define it as static const in SplashOutputDev since was used in various places
MapNumericCharNames: true, remove GfxFont.cc if guard
MapUnknownCharNames: true, remove GfxFont.cc if guard
6 files changed