canvas-getter-v0.1.1

Features:

• Added optional days CLI parameter:
  for example, runcanvas_getter.exe 3 to filter last 3 days
• default days changed to last 7 days
• output much improved:
  
• use the "clear-cache" cli command to delete and remake every output_dir directory

Notes:

• immense internal refactoring
• fixed: curl now follows redirect and downloads files