PWM method efficiency improvements and MoonPhase whitespace cleanup

Three real changes:
1) Call hour() only once in PWMSlope() and PWMParabola(). We lose 2 bytes of memory but save a whole bunch of work in the AVR, relatively speaking.
2) In PWMParabola, move calculation of pwmDelta and parabolaPhase into the else block rather than calculating them every time PWMParabola is called.
3) Whitespace cleanup for PWMSlope(), PWMParabola(), and MoonPhase(). These all had mixed tabs and spaces for indentation, I've switched them to tabs because they were mostly tabs (and personally I prefer tabs). Not sure if there is a project standard about this.