improvements for /skip command

1. Allow cancel "/skip" command execution in any moment (by entering /skip command again);
2. Make /skip obey to settings that applied to catchup settings (Catch up smoothness, Catch up min fps). My goal here to catch up as faster as i can.

Start by locating the /skip command entry point and the existing catchup settings for smoothness and minimum FPS. Verify how /skip execution progresses and how those settings are applied. Done means entering /skip again cancels an active skip and skip catchup follows both specified settings.

Written by the indexing model from the issue text.