timing measurement rollout

[fabriceo]

Hello,
I think there is a bug in this code

lib_i2c/lib_i2c/src/i2c_master.xc

Line 69 in 6e1b8ad

if (time > fall_time + delay + wake_up_ticks) {

when time > 2^31 , after about 10 seconds, the comparaison is not working as expected.

a safe approach would be to declare any time variables as signed integers, then subtracting them (new-old) and verifying if result is below or above something.