- add keystrokes for launching input manager (Ctrl-F9) and spectrum analyzer (Ctrl-F10)
- move Hide and Clipbox plugins from transforms to special category
- remove a last-statement 'return'
add gui/images/buttons/directory-up.png
- remove unneeded return
- add basic image file chooser with thumbnail previews
- add tumblr link to readme
- add basic UserObjectSettingDirector support
- remove Engine's new_user_object_class callback, not needed in 2.0
- remove Engine's update_user_objects callback, not needed in 2.0
- remove Engine's user_object_changed callback, not needed in 2.0
- remove Engine crash callback, unused in 2.0
- comment
- remove unused instance variable @num_known_user_object_classes
- move USER_OBJECT_EXCEPTION_FORMAT out of engine to where it's used
- remove duplicate declaration of BASE_SET_PATH
- add ProjectEffect#pretick! for consistency with tick!
- comment
- comment
- cleanup