Working better with (hopefully) less bugs

This release changes the way that Better Bookmarks works as it's the first major refactor of this project.

Changes

• Removed BBFile and global list of files as it was confusing and cumbersome and actually wasn't needed at all!
• Moved all of the Better Bookmark prefixed commands to a single TextCommand.

Additions

• Added the ability for the user to choose where the layer switch information shows up.

Bug fixes

• Saving and loading of bookmarks is now actually working.
• The paths to the image files are correct for production now.
• Improved detection of whether or not to save bookmarks (previously it would create files with no marks in them).