Keep supporting 'srun -N x --pty bash' for historical reasons.
Fix for ntasks_per_core with cpus_per_task

This reverts commit 859839a73ca2a65ed6d5b7c9cffdc51dcaf29250
The ntasks_per_core option was previously really treated like number of CPUs (rather than tasks) to allocate per core, which seems to be what is desired.
Merge branch 'slurm-14.03'