Rename wfsubtrack2 task to wfpolarize

Make sure that the task is clearly separated out into it's own .c file in
case we want to later add a wfpolarize skin to compliment the orbpolarize
skin.
remove stub comments
Change NSL_COMP_SZ to NSCL_COMP_SZ
Fix typo NCSL should be NSCL
Change component match regex strings to defines
Make wfpolarize_get_prefix_from_chan reusable

Converted _get_prefix_from_chan to a reusable function
Add caveat about schanpre being previously allocd
clarify size better
Change get_prefix_from_chan to use regex

Expanded regex to include more horiz channels
Process dbmaster into channel tuples

Add quick test_skin executable to test the dbmaster parsing function

Add function to process dbmaster, and group tri-axial sensor channels
into channel tuples. Excludes database segtypes that are not A or V.
Groups channels into clusters by SEED snet, ssta, schanpre (a SEED channel name
prefix, ie the HH part of HHZ), and sloc.

Still to do: change channel tuple grouping to work with a set of
preferred schanpre codes