Travis CI: site documentation update at 2014-02-15 05:50:08 UTC.

Commit: https://github.com/urho3d/Urho3D/commit/8ef4dc47eb180a9f077189af34fb3f858d1ff551

Message: Better integration of MinGW cross-compiling build process.

- Runtime and archive output directories change to mingw-Bin and mingw-Lib, respectively.
- Enable SCP_TO_TARGET build option for all cross-compiling build process (except Android).
- Enable LuaJIT support for MinGW cross-compiling build.
- Cache MinGW toolchain path and sysroot.
- Fix "object file is too big" issue when building Assimp library in debug build using MinGW.
- Reorder the build processes documentation section to match the Readme.txt file.