[Swift-user] pbs ppn count and stuff

[Mihael Hategan]

So I think some of the problems with ppn are as follows:
1. count in cog means number of processes. count in PBS means number of
nodes.
2. when the number of nodes requested was 1 but ppn > 1, the multiple
job scheme was not enabled so, despite having multiple lines in
PBS_NODEFILE, only one process would get started. If count was > 1 then
PBS would understand that count*ppn lines should be in PBS_NODEFILE,
which would result in that number of processes be started. In other
words there was no way to tell PBS to start 4 jobs on only one node.

So:

- I changed this to be consistent with 1. Count means number of
processes to be started. This imposes the restriction that count % ppn =
0. If not, the pbs provider will throw an exception. 
- I also added mppnppn if USE_MPPWIDTH is enabled.

This is in trunk.

Mihael