Track random seeds

[jvdzwaan]

Related to #48; possible solution is #104 (although it is not effortless)

[robintw]

Yes, this is definitely something we should do - unfortunately I can't see an effortless way at the moment. We'd need to wait until modules like random or numpy are imported, and then grab the seeds...but of course the seeds may be set manually sometime after they're imported (tho I guess that will be in the code that we grab too).

We could potentially put some sort of callback/hook into our 'module loading hook' that will grab important information about the module that has been imported. In this case it could include the random number seed (eg. np.random.seed), but could also include versions of the modules/dependencies - also fixing #87

[robintw]

See http://stackoverflow.com/questions/32172054/how-can-i-retrieve-the-current-seed-of-numpys-random-number-generator for info