Add program which dynamically loads NVML from OCaml

Signed-off-by: John Else <john.else@citrix.com>
Tweak error handling in ml_dlopen

Signed-off-by: John Else <john.else@citrix.com>
Load some symbols

Signed-off-by: John Else <john.else@citrix.com>
Add to .gitignore

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