Stereo support, new water and physics callbacks

Recent changes:

• Stereo mode in the render.
• New ObjectWater instead of old water.
• Refactoring of particles shaders.
• Fixed issue with required D3DPTADDRESSCAPS_BORDER for ATI R400 and R300 (it doesn't support border clamp according to the spec, however it works ok).
• Physics callbacks for joint destruction, freezing and new contacts.
• More efficient memory allocations for physics.
• 3 more physics samples (callbacks, freezing).
• foreachkey() now iterates over ordinary vectors in UnigineScript.
• New check() function for maps (it checks validity of a key).
• Fixed jpeglib build for Windows.
• "intersection" function is renamed to "getIntersection", the same is for collisions in meshes.
• "world_clear" console command is renamed to "world_quit".
• object.setMaterials removed; everything works by means of object.setMaterial.
• Fixed bug with button handling for non-focused widgets in GUI.
• engine.gui.setCallback function is renamed to engine.gui.addCallback.
• New "editor_script" console variable for multiple editors.
• "Come to me" button in UnigineEditor: it moves selected object right in front of the camera ('b' hotkey).
• Fast simplified rendering mode in UnigineEditor (modes are toggled by 'F3' button).
• Updated documentation on console variables and commands.
• "Programming / UnigineScript / Script Debugging Tips" article in the manual.
• Updated "Tools / UnigineEditor" article in the manual.

Here is the table describing combinations of "render_stereo" console variable's values and postprocessing materials to be used with different stereo output devices:

A special small launcher is required for stereo mode on Windows since it works via an interesting trick. Users can enjoy stereo mode on Linux as well.