implement some of save_file
add color information to stand_templates in save file
fix function prototypes and print_stand_templates
implement print_stands
merge saving branch
add stands block header
nicely space output and replace default_sale.mmgs with new nicely-spaced version
add save_user_file to api
hook up saveUserFile in frontend
- added new field to window object: curFileName, to remember the filename
  for SaveMap
- current default filename is "untitled.mmgs"
- SaveMap connected to Save menubar button and Ctrl-S accelerator
fix bugs in load_stands
- return type was wrong (needs to be int32_t to return number of loaded stands)
- non-zeroed memory for new stands was affecting NULL tests, causing SIGSEGVs
add missing filename update