Enable CharacterDemo & VehicleDemo also without networking. Update documentation.

Docs/GettingStarted.dox

@@ -219,7 +219,6 @@ Execute cmake_mingw.sh then go to the build tree to execute make command. After
 \section Building_Emscripten Emscripten build process (EXPERIMENTAL)
 
 > WHAT DOESN'T WORK:
->    - %Terrain rendering.
 >    - Networking. Javascript can only use http and websockets protocols so it's not likely that kNet will ever function.
 >    - All the scripting support: AngelScript and Lua/LuaJIT.
 

Source/Samples/CMakeLists.txt

@@ -60,6 +60,8 @@ if (URHO3D_PHYSICS)
     add_subdirectory (11_Physics)
     add_subdirectory (12_PhysicsStressTest)
     add_subdirectory (13_Ragdolls)
+    add_subdirectory (18_CharacterDemo)
+    add_subdirectory (19_VehicleDemo)
 endif ()
 if (URHO3D_NAVIGATION)
     add_subdirectory (15_Navigation)
@@ -69,8 +71,6 @@ if (URHO3D_NETWORK)
 endif ()
 if (URHO3D_NETWORK AND URHO3D_PHYSICS)
     add_subdirectory (17_SceneReplication)
-    add_subdirectory (18_CharacterDemo)
-    add_subdirectory (19_VehicleDemo)
 endif ()
 add_subdirectory (20_HugeObjectCount)
 if (URHO3D_ANGELSCRIPT)