seznam/JAK — pull request #133 by ethanius (2014-10-08 10:53:36+00:00)
Title: Not so strict behavior in removeListener

After some debate it has been decided to fail almost silently when removing a non-existent listener. The developer still gets the message (in form of a console.error() call) that warns him about a possible flaw in his code but the application does not break.