Sessions 0.7.3 referencing wrong icons

When Sessions 0.7.3 is used with JEdit 4.1pre4 and the
session switcher is added to the toolbar, none of the 4
buttons added along with the switcher have icons
associated with them and therefore it looks like they
haven't been added. The reason for this is that the
names of the icon files are hardcoded within
SessionSwitcher.java and they still reference the old
icon files within the JEdit jar. The names of the icons
have been changed when the new icons were
introduced. Updating the references to the files in
SessionSwitcher.java fixes the problem, but this
obviously doesn't help the people who are still using an
older version of JEdit with the old icons and old file
names.