Travis CI: site documentation update at 2014-07-17 07:30:14 UTC.

Commit: https://github.com/urho3d/Urho3D/commit/08f08e460b92ceb183f31a31545dbe255e6d47ec

Message: Improve the reliablity to find SDL_android_main.c when using SDK.
Replace usage of URHO3D_INSTALL_PREFIX environment variable with the more standard CMake's own CMAKE_PREFIX_PATH environment variable to define prefix path of non-standard SDK installation location.