KPL_Mask: Add POD Documentation

Seems reasonably straightforward when you use 1000 words to describe it.
KPL_Mask: Create Routine to Calculate Proper Bit Masks
Insteon_KPL: Add Peek/Poke Commands to Enable IntraDevice Links
Merge branch 'insteon_kpl_mask' into running
Insteon_KPL: Only Poke New Bytes if They are Different

No need to push byte if the address already contains that value.