Fix words tacked on the end of a sentence.
Fix use of wrong macro.
Add first version of MRG for gpuarray (with tests).
Change GPUA_mrg over to use GpuKernelBase.  (I couldn't get it to work otherwise).
Remove useless import of NVCC_compiler
Add checks for copies and reassure observers that ga_int is 32 bits.
Merge pull request #1697 from abergeron/gpua_mrg

mrg_rng for gpuarray