added event actions (by simulating keyboard input) for global animations

added event actions (by simulating keyboard input) for global animations

This change adds more event actions to the "anim_event_action" option
for clickable global animations, this time adding simulated keyboard
input by specifying a key symbol for the key to be simulated.

For example, you can now use:

global.anim_1.part_1.MAIN.anim_event:            click
global.anim_1.part_1.MAIN.anim_event_action:     XK_Return

When clicking this global animation (on the main menu screen), the
currently selected/highlighted menu item will be chosen/executed.

To get the key symbol/name for the key to be simulated, just choose
the desired key as a keyboard shortcut in the setup menu (temporarily
only) and look at the resulting entry in the file "setup.conf" in the
game's configuration and personal data directory.