added an incomplete zoom

Press F8 to toggle zoom mode. Move with the arrow keys.
The current zoom has 3x3 zones in each square, labeled N, S, E, W, NE, NW, SE, SW, and no label for center.
Merge branch 'master' into continuous

Conflicts:
	res/ui/tts.txt
	soundrts/clientgame.py
zoom: local selection, Tab, 1..4, Q

TODO: order with zoom as a target
refactoring: extracted clientmediamouse.py from clientgame.py
translated in English some functions in clientgame.py
refactoring: extracted clientgamegridview.py and clientgameorder.py from clientworld.py
cleanup: deleted unused tests
renamed clientworld.py clientgameentity.py
refactoring: extracted clientgamenews.py
renamed clientgamezoom.py clientgamefocus.py
Merge branch 'master' into continuous
now it is possible to use the current center of the zoom as a target for a "go to" order

the first point of patrolling isn't defined perfectly yet, because the starting square is used instead of the exact coordinates of each unit
added display for zoom
strategic commands like "select next scouted square" end zoom mode
added: zoom changes the listener position, Control triggers a description of the zoomed zone
translation and refactoring of GameInterface.mode
refactoring: removed GameInterface.mode, only use GameInterface.order
zoom: added follow mode
removed unused constants and fixed the code to pass a test
updated the manual about zoom mode