parser.py is designed to parse a summary report from SAPGUI, combine GLs into
categories using a user-defined mapping, and produce a summary file with totals
for each of the categories.

parser.py takes three filename arguments:
* summary: the SAPGUI summary report (exported using the "download" function)
* accounts: account/category mapping file. The first column should be the category, and the second should be the account name (specifically, as it appears in the summary report --- which has a column of "     account number - account name" type elements). Additional columns may be included, but will be ignored. This may be useful for leaving notes for yourself about why an account is in a particular category.
* output: CSV output file

parser.py will read the first two files, write CSV output into the output file,
and save some notes (e.g., summary rows that don't look like they have relevant
info, accounts without a category, etc.) to stdout.

To use SAPGUI to get the summary:
1) Run "add sapgui; saplogon" from an Athena machine
2) Type "ZSTM" into the box at the top and hit enter to load the summary report settings page
3) Fill in the appropriate fiscal period (probably 12/YYYY) and cost center (into the "cost object (unknown type)" box)
4) Run the report (hit the clock with the checkmark) and click through the warnings
5) Select the "download" option and save the file somewhere relevant

To create the accounts file, you can run the program with an empty one (e.g.,
/dev/null) and grep for lines starting with "Misc". Modify the text you get
from that to replace all the "Misc" categories with useful names, and then
rerun with that as your accounts file.