[et-mgmt-tools] Making labels selectable in properties dialog

[Rob James]

Hi all, i was trying to make a label in the properties dialog
selectable to make it easy to copy and paste the value (specifically
the "source path" value under Disk). I tried using glade-2 to do it
which works but seems to screw up the alignment of pretty much
everything else. Is there something obvious I'm doing wrong?

-R