Remove bom(b) from Readme.txt and update the project tagline.

Readme.txt

@@ -1,5 +1,5 @@
-Urho3D - cross-platform rendering and game engine
--------------------------------------------------
+Urho3D - cross-platform 2D and 3D game engine
+---------------------------------------------
 
 http://urho3d.github.io/
 

Source/CMakeLists.txt

@@ -86,7 +86,7 @@ file (GLOB CMAKE_SCRIPTS ${PROJECT_ROOT_DIR}/${SCRIPT_PATTERN})
 install (FILES ${CMAKE_SCRIPTS} DESTINATION ${DEST_SHARE_DIR}/Scripts PERMISSIONS OWNER_WRITE OWNER_READ OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
 
 # Setup package variables
-set (URHO3D_DESCRIPTION "Urho3D is a lightweight, cross-platform rendering and game engine implemented in C++ and released under the MIT license. Greatly inspired by OGRE (http://www.ogre3d.org) and Horde3D (http://www.horde3d.org).")
+set (URHO3D_DESCRIPTION "Urho3D is a lightweight, cross-platform 2D and 3D game engine implemented in C++ and released under the MIT license. Greatly inspired by OGRE (http://www.ogre3d.org) and Horde3D (http://www.horde3d.org).")
 set (CPACK_PACKAGE_DESCRIPTION_SUMMARY ${URHO3D_DESCRIPTION})
 set (URHO3D_URL "https://github.com/urho3d/Urho3D")
 set (CPACK_PACKAGE_VENDOR ${URHO3D_URL})