Make `index` argument optional and return curve in `remove curve from playlist`.
-rw-r--r-- 114 .gitignore
-rw-r--r-- 474 .mailmap
-rw-r--r-- 1892 .update-copyright.conf
-rw-r--r-- 380 AUTHORS
-rw-r--r-- 14414 CHANGELOG
-rw-r--r-- 35147 COPYING
-rw-r--r-- 7639 COPYING.LESSER
-rw-r--r-- 2519 README
drwxr-xr-x - bin
drwxr-xr-x - conf
drwxr-xr-x - contrib
drwxr-xr-x - doc
drwxr-xr-x - hooke
-rw-r--r-- 2267 setup.py
drwxr-xr-x - test