Use GtkFileChooserButton to setup library location
Submitted by Luca Ferretti
In preferences dialog, Rhythmbox is currently using a simple text entry plus a button to choose the library's directory.
The "right" widget here should be a GtkFileChooserButton in select folder mode. The same widget is yet used in Podcast section to set up the download directory for podcasts.
Please also note that there is a GNOME HIG rules breakage here: the text entry (same will occur with GtkFileChooserButton, it's a drop down list) should have a text label providing an access key. On current setup the label is missing and the access key is on section header (bolded text).