Fix alignment of items in tooltip when using GTK2
Use eggtrayicon which has better transparency support (taken from UIM project)

The original eggtrayicon which was bundled with mail-notification ceased
to work properly on modern desktop environments. Transparent icons
didn't work correctly any more. An attempt was done to port
mail-notification to use GtkStatusIcon, but unfortunately this required
a rewrite of a large piece of the mail-notification which isn't feasable
for now. The UIM project has done an excellent job at keeping
eggtrayicon in working condition for both GTK2 and GTK3 environments
so we replace our copy of eggtrayicon with the eggtrayicon code from
the UIM project
More indenting improvements
More indenting improvements
Fix potential source of crasher bugs

Might resolve the crasher bugs mentioned at
https://bugzilla.redhat.com/show_bug.cgi?id=531088
Resolve segfault when a configuration error was detected on startup (RHBZ #847543)

See https://bugzilla.redhat.com/show_bug.cgi?id=847543 for details and backtrace
Properly unrealize the tray icon

In commit fa55ad a more modern version of eggtrayicon was used.
However, it turned out that it caused tray icons to remain visible
on the screen even when they should be destroyed. Worked around this
for now as I'm uncertain what the proper fix is
Replace gtk_paint_box with cairo calls

The function gtk_paint_box was used to draw a box containing
the number of new mails in the tray icon. For some unknown reason
this has been broken for some time. On modern environments this
function only draws a gray non-transparent box without any borders.
As this makes the tray icon look ugly the code in question was
rewritten using cairo API functions
Make sure the tray icon is drawn initially with the correct dimensions