Building and installing HHVM on CentOS 5

Building and installing HHVM on Old CentOS5, without internet access, building HHVM by scripts: Please refer to:

https://github.com/jackywei/HOW-TO-BUILD-HHVM-WiKi/wiki/Build-HHVM-in-CentOS5.2-(w-o-internet-access-for-build-env.)