Added comments. Defined constants. Separated debounce timers. Added f…

…lag to disable switching.

I am more than guilty of doing too much in a single commit.

Added a ton of comments so that newbies might get it.
Changed variables that were used as constant to just be #define 'd
instead. No more magic #s?
For some reason I was using a single debounce timer for both buttons.
Fixed. In addition added debounce to single button press mode.
Added CAN_SWITCH_MODES for those who just want one mode or the other.