Menus: Remove background member variable as it is already in Menu base class
AStar(Close)Container: have an unimplemented copy constructor

The classes AStarContainer and AStarCloseContainer did not have copy
constructors, which is recommended since the classes contain pointers
to allocated memory.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
added an option to hide labels and made some copy/paste cleaning
Fixes for option to show hotkey names

* Adds the checkbox to menus/config.txt
* WidgetCheckBox's constructor does a call to mods->locate() already, so
passing the results of mods->locate() to the constructor caused a crash
* Use the SHOW_HOTKEYS boolean in MenuActionBar instead of maintaining
a private variable
* Fix the spelling of placeLabeledCheckbox()
Merge pull request #1 from dorkster/showkeynames

 Fixes for option to show hotkey names
Merge pull request #764 from bmorel/show_keynames

Show keynames
added show_hotkeys_cb to tablist
Merge pull request #773 from bmorel/show_keynames

added show_hotkeys_cb to tablist
Merge pull request #771 from stefanbeller/master

Small code cleanups