modify running behaviour a little

now uses ctrl instead of shift, same key as strafe.
strafe = single square movement while holding ctrl.
run = more than one square movement while holding ctrl.

path preview will now correctly colour the tiles for running movement.
add HQX button in options menu

toggles hq2x scaler with opengl disabled, or switches filters if enabled.
(if you're on the default filter or the one it switches to, i only set it
to toggle between the standard Openxcom shader and the HQ2X shader)
Add advanced options menu.

adds an "advanced options" menu to adjust some of the gameplay elements
Add strings for advanced options menu.

i apologise in advance to the translators for all the extra work i've just
created for you.