Change run_neon to run from any directory and add some additional options for testing

[ekluzek]

In ctsm5.1.dev052 the run_neon.py script that runs NEON sites, can only be run from the directory it exists in. In order to enable the tools testing this needs to be extended to run from any directory.

There are some other features that would be useful for system tool testing such as being able to:

• set if it should only setup the case and not build it.
• And to set the length of the simulation.
• From being called from the system tool tests it should also have an option to run directly rather than being submitted to the batch queue.

Some of this could be handled by adding a general service option (similar to --extra-create-test-args for run_sys_tests) to send an argument directly to the invocation of newcase. this won't work since it's not being called on the comand line

@negin513 @jedwards4b