Fixed imports for installing from a git clone (#24)

.gitignore

.idea/.gitignore

CHANGELOG.txt

__init__.py

core/__init__.py

core/folder.py

core/key.py

core/translations.py

memory.py

menus/__init__.py

menus/folder_icon.py

menus/shape_key_add_context_menus.py

menus/shape_key_copy_context_menus.py

menus/shape_key_other_context_menus.py

menus/shape_key_parent.py

menus/shape_key_remove_context_menus.py

operators/__init__.py

operators/driver_update.py

operators/folder_icon.py

operators/folder_mutate.py