Add varying rdim for DMD time windowing

[ckendrick]

This adds an option to the DMD time windowing examples local_tw_csv and parametric_tw_csv for specifying an additional input file containing a reduced dimension or energy fraction value for each window, rather than using the same -rdim or -ef value for all windows.

Example csv input file specifying rdims for each window index:

RDIM
0,6
1,7
2,8
3,10
4,9

The csv input file is assumed to be in the DMD list directory, similar to the other inputs used by local_tw_csv and parametric_tw_csv. The above example can be modified to specify energy fraction values by using EF in the header.