Add checks for inefficient resource usage

Add checks for inefficient resource usage

Checks have been added for using too many OpenMP threads and when
using GPUs for using single OpenMP thread. A fatal error is generated
in case where we are quite sure performance is very sub-optimal. This
is nasty, but a fatal error is the only way to ensure that users don't
ignore this warning. The fatal error can be circumvented by explicitly
setting -ntomp, in that case a note is printed to log and stderr.

Now also avoids ranks counts with thread-MPI that don't fit with the
total number of threads requested.

With a GPU without DD thread count limit is now doubled.

Disabled GPU sharing with OpenCL.

Change-Id: Ib2d892dbac3d5716246fbfdb2e8f246cdc169787