Feature/ae add pulse candidate finder to generator

So I've added the PulseCandidateFinder to FirstCompleteAPGenerator and made a couple of tweaks:
 - for fast pulses we take 2 bins before the "detected" start so that we get the whole pulse (muSc pulses were looking a little odd)
 - for slow pulses we track back from the "detected" start until we hit the pedestal to get the whole pulse (I could also do this for fast pulses)
 - tweaked a parameter value:
  - ScL: rise 20 --> 15 because run 2808, event 0, pulse 2 had obviously missed a 4th candidate pulse

I think there are still a few channels to tweak the parameter values for (Run 2808, SiL2-S, event 8, pulse 1 has two candidates when there should only be one) but I will leave this till tomorrow since it would be nice to run with this today.

Also, for the Ge-F pulses, there are some overflows which mean we are detecting pulses when we shouldn't (just a heads up):
![ge-f_overflowedpulse](https://cloud.githubusercontent.com/assets/1848575/3799815/82d3a32c-1bf1-11e4-934a-7ae940a5f60f.png)

Note, there are 5 candidates here.

(I've got to dash off home now so can't do any more work on it - I should be able to reply to comments with my GitHub smartphone app :) but can't do any coding because my laptop is broken :( ).