WebUI: Apply UrlDecode on post parameters.

This fixes seeking though the WebUI.
WebUI: Fix volume slider going out of bounds with IE in player.html
apply astyle
Fix: Disable the "Tearing Test" menu entry when it isn't supported.

This commit fixes ticket #2844.
fix VSFilter x64 compilation
Fix: The "Display Stats" menu entry was disabled while still available.

This feature doesn't require 3D texture surfaces.

This commit fixes ticket #2819.
Cosmetics: Make the checks for the "Renderer Settings" menu more consistent.
fix line endings
WebUI: rename a few css classes, sort the properties by name
WebClientSocket.cpp: add line breaks to the produced html code
WebClientSocket.cpp: remove non existent css classes
Cosmetics.
"Play > Filters" menu: simplify the items' state handling.

This menu is dynamically built so there is no reason to use an extra function to set the state of its items. The states are now set correctly when building the menu.

Note that thanks to this change the new UI style is now used for the radio bullet.

This commit fixes ticket #1620.