Repeatable randomization (CUDA).
THC: revamped random engine.

The seed is now changed each time a new vector is sampled.
This was done in order to decouple our engine as much as possible from
the internals of Thrust.
Merge github.com:andresy/torch into andresy
Merge branch 'andresy'

Conflicts:
	extra/cuda/lib/THC/THCTensorRandom.cu