Initialize random seed during CUDA initialization.

Initialize the random seed for all GPUs during CUDA initialization rather than
when the device is set.
Merge pull request #45 from dominikgrewe/random_seed

Initialize random seed during CUDA initialization.
test.lua can now be either run as standalone or as part of the package cutorch.test()
upped the minimum cuda version to 5.5 to fix concern in #43
Merge remote-tracking branch 'upstream/master'