Compile Qt 5.2.0 with ICU

Finally find a way to compile Qt 5.2.0 with ICU. It seems the PATH, LIBS and INCLUDE environment variable somehow being reset/ignore during the build process. So, in order to help the compiler and/or linker to find ICU libraries, I've copied all the ICU development files to Qt source tree and the compiler and/or linker now recognized the existence of ICU libraries and build Qt 5.2.0 shared version successfully with WebKit support.