Convert build to OASIS 0.3.0

Signed-off-by: John Else <john.else@citrix.com>
Rearrange source code

Move src/nvml* to lib/
Move src/rrdp_gpumon.ml to gpumon/gpumon.ml

Signed-off-by: John Else <john.else@citrix.com>
Merge pull request #2 from johnelse/oasis-build

OASISify and rearrange source code