write_master.py creates a master Excel file for
automated DLB runs from a series of text files.
See usage and other notes in function doc string.

fix bug in channel naming of flap angles

refer to python environment on cluster

controler tuning file to tag conversion now part of prepost.hawcstab2

reading HS2 pwr file header containing gradients

add method to write out all tags from master file into an Excel sheet.

this is used to avoid wine/HAWC2 locking 2 instead 1 thread per sim

Note that this illustrates that a documented and consistent tag
standard naming scheme is long overdue!