misc: add myself as maintainer

1) GNOME Flashback needs new release for gnome-panel, but current
maintainers does not show any interest in bug fixes and/or
improvements to this module.

2) Current maintainers are inactive. Jonathan does not object that
I am taking over maintainership.

3) I am already maintaining other modules used by GNOME Flashback
session - gnome-applets, gnome-flashback, metacity and
notification-daemon.

4) No response to this email:
https://mail.gnome.org/archives/gnome-flashback-list/2014-September/msg00033.html
wncklet: remove unneeded code and rename function

Function panel_applet_add_preferences was used only with gconf,
but applet now uses gsettings to store/read settings so this
function is not needed anymore.

Renamed function setup_gconf to setup_gsettings as it is more
correct name for this function.
panel: replace gtktable with gtkgrid in panel-ditem-editor.c
panel: remove unused variables from panel-layout.c
panel: port panel-util.c to gsettings
notification_area: remove unneeded include
panel: remove unneeded include in gnome-desktop-item-edit.c
panel: remove gconf from panel-action-button.c
panel: port panel-menu-items.c to gsettings

Only home-icon-name is ported. desktop-is-home-dir and
computer-icon-name is removed from Nautilus.
clock: remove unused #define line
panel: replace gtktable with gtkgrid in panel-toplevel.c
panel: don't set panel's initial size to G_MAXINT

Replacing GtkTable with GtkGrid introduced new bug. Warning is -
'Native children wider or taller than 65535 pixels are not supported'.
This is caused by setting panels initial size to G_MAXINT. Changing
initial size to 0 fixes this new bug.
Remove g_type_init(), bump GLib required version
remove deprecated librsvg/rsvg-cairo.h include

Direct include of librsvg/rsvg-cairo.h has been deprecated from
2.36.2 version. Removed it and added required version for librsvg.
port bindings to gsettings
don't use deprecated GtkSymbolicColor

Code for color shading copied from mutter:
https://git.gnome.org/browse/mutter/tree/src/ui/theme.c
Fix window-list applet bug on vertical panel
03_tasklist_orientation.patch from debian. This requires libwnck
3.4.6 or newer.
xstuff.c: remove old unused code
panel-icon-chooser: don't use deprecated GtkStock
panel.c: don't use deprecated GtkStock