[Bug 31612] do not show message dialogue after successfully saving playlist

[Jonathon Conte]

Public bug reported:
https://launchpad.net/malone/bugs/31612

Affects: serpentine (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
I'm running Serpentine v0.6.9.0 in Dapper Drake (testing). Upon
sucessfully saving a playlist, Serpentine displays a dialogue window
informing the user of this fact. There is little use for a dialogue
window that does not ask the user a question or offer a choice. This
window only serves to distract the user with an unecessary button click
so I recommend that it be removed.

There are other ways that Serpentine could convey whether or not the
playlist is currently saved such as using the playlist filename in the
titlebar of Serpentine's main window.