Conversion to-do's

[darcymason]

From hand edits, keeping notes on some improvements noted for auto-transpiling:

• [ ] fix conversion of macros that were made completely blank, e.g. $PARTICLE-SELECTION-...
• [ ] check LHS of assignments for common block variables, and put in the common block name
• [ ] in parsing macro files, skip / ... / lines (like second $COMPUTE-RANGE that was commented out)
• [ ] try to put minus one "_m1" variables in for common block array indices