Store the main window maximized state in the configuration

In save_window_geometry() use gdk_window_get_state() to retrieve
the window maximized state and store it in the user configuration.
Then in restore_window_geometry() restore the maximized state with
gtk_window_maximize(), if needed.

To achieve good results we also need to override "window-state-event"
for the main window and define an extra couple of configuration parameters:
"vpane_position_maximized" and "hpane_position_maximized".
Then store two different pane states for maximized and restored window each
time the user makes a switch.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
gtk-gui.c: Some small whitespace indentation fixes

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Make relative times default in planner 2

In planning you usually plan lengths of segments rather than runtimes to
leave a level.

This patch superseeds a previous one with a similar name and (even more)
broken spacing.

Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>