2006-01-21  Srirama Sharma  <srirama.sharma@wipro.com>

	This patch is union of patches given by Leena Gunda and Christian
	Neumair along with some minor modifications; it synchronizes the
	right-click-menu with that of Metacity's.  #135710.

	* libwnck/screen.c :
	(wnck_create_window_action_menu): Add "Move to Workspace Left/
	Right/Up/Down" menu item.
	(item_activated_callback): Implement code to move the window to
	the workspace at left/right/up/down.

	* libwnck/screen.h :
	Added the WnckWorkspaceLayout and WnckMotionDirection structure.

	* libwnck/window-action-menu.c :
	(wnck_screen_get_workspace_index): Get the index of the
	workspace.
	(wnck_screen_get_workspace_neighbor): Get the neighbor of the
	workspace in specified direction.
	(_wnck_screen_process_property_notify): If the workspace layout
	has changed, call the idle handler to update the screen info.
	(wnck_screen_calc_workspace_layout): calculate the workspace
	layout.
	(wnck_screen_free_workspace_layout): free the layout grid.
	(update_workspace_layout): idle handler to update the screen
	info. if the layout has changed.
	The code to calculate the workspace layout is taken from
	metacity sources.
	(make_check_menu_item): create a check menu item with the given
	mnemonic text.
	(update_menu_state): replace the Roll up/Unroll menu item with
	On Top check menu item.

	* libwnck/window.[ch] :
	(wnck_window_make_above): Put the window on top of all window.
	(wnck_window_is_above): check whether the window is above all
	other window.
	(wnck_window_unmake_above): if the window is on top then uncheck
	the menu item.