more general run sequences need to be supported

[mvertens]

If the following occurs in CMEPS an error will be triggered. The run sequence generation needs to be generalized to allow for these cases:

1. atm_cpl_dt > ocn_cpl_dt: This is the case for a C compset right now in cpl7, where datm couples every 6 hours but the ocean couples every hour. This is current not a generated run sequence and needs to be supported.
2. rof_cpl_dt < ocn_cpl_dt This also occurs in a C compset configuration for cpl7.

The error is triggered in runseq_general.py.