|Create a delay loop that can loop for up to 2^16 times while mininmizing
|the number of cycles per iteration.

More fun variant: write a routine which, when called, will time how long
it takes for pin RB7 to go high [assuming it isn't already].  Time should
be kept in 16 bits, and the routine should exit if RB7 does not go high.
within 65,536 counts.

To make things a bit more interesting...

[1] Consider approaches with and without RTCC

[2] Try for a measurement precision of 3 cycles.

[3] Try to design the loop to look for either port pin RB6 or RB7 to
    go high, with a precision of 4 cycles.

Those sound like fun little additions?  I will offer a couple little hints:

[A] The code need not LOOP 65536 times; if you have, e.g., two tests within
    a 6-cycle loop you could run the loop 32768 times and at the end check
    which test kicked you out of it.

[B] You need not exit the loop immediately upon detecting the event, prov-
    ided the count values are correct.

Have at it...