Clean scaling pre-filter for formspec/HUD.

build/android/jni/Android.mk

minetest.conf.example

src/CMakeLists.txt

src/client.cpp

src/client/tile.cpp

src/client/tile.h

src/defaultsettings.cpp

src/drawscene.cpp

src/guiEngine.cpp

src/guiFormSpecMenu.cpp

src/guiTable.cpp

src/guiscalingfilter.cpp

src/guiscalingfilter.h

src/hud.cpp

src/imagefilters.cpp

src/imagefilters.h

src/touchscreengui.cpp

src/touchscreengui.h

src/util/numeric.cpp

src/util/numeric.h