Updated Sensor library keywords.txt
Implemented DeltaTimer to use in update loops.
Replaced CrystalBallProgram with crystal_ball sketch.
Replaced DigitalHourglassProgram with digital_hourglass sketch
Replaced KnockLockProgram with knock_lock sketch.
Replaced LedTempProgram with temp_controlled_led sketch.
Updated PiezoSpeaker to use NewTone library.

NewTone is compatible with NewPing whereas the built-in tone() is not.
Replaced LightThereminProgram with light_theremin sketch.
Replaced MoodCueProgram with mood_cue sketch.
Updating keywords.txt in LED library.
Replaced MotionNightLightProgram with motion_night_light sketch.
Updating keywords.txt in Motor library.
Replaced PinwheelProgram with pinwheel sketch.
Replaced a couple of RGB LED test programs with rgb_led_test sketch.
Removing some unused code.