#223: Fix waveform length when merging pulses

[phlipped]

Fixes issue #223

[phlipped]

While I'm here ... It seems to me that the if-blocks like "if (tNow < tNext1) ..." (lines 3233, 3250, 3267) will never get executed, and can be safely removed.

tNow will always be equal to the smaller of tNext1 and tNext2 (because of lines 3282,3283. This is also true at first iteration - tNow is 0, and at least one of tNext1 and tNext2 must be 0). Therefore, if (tNext1 < tNext2) (line 3229), then (tNow == tNext1), and the conditional (tNow < tNext1) (line 3233) will always be false. The same idea applies to the other two places (lines 3250 and 3267)

[joan2937]

This fails a couple of tests in x_pigs and x_pipe which should pass. I'll need to revisit this at a later date.