Hiding active, visibility, and image_path, and making them properties. Its a bit more logical how the  parent widget to interact with the label now.
Changing the folder structure.
Removing the ability to set the value of the label after creation. Removed superfulus conditional for active icons visible in set_icons_active.
Removing todo notes. Fixing up _get_visible return values to be correct after breaking them.
Adding some tests. num_icons, set_icons_active, active_icons_visible.
Merge branch 'develop'