Add pbspro specific _qsub_command implementation using select/place options.
Add pbspro specific _qsub_command implementation using select/place options.

select/place syntax is the modern way of specifying a resource list with
PBSPro. This has not yet been tested when a hostlist is specified.

CoryMcCartan/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel,chizarlicious/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel