* Replace Ubuntu scons dependency with cmake
* Remove dependency installation support for Ubuntu 12.04 Precise Pangolin.
It is EOL'd as of 2017-04-28. http://releases.ubuntu.com/12.04/
In some cases this script did not detect properly that the subprocess is already terminated. The "append" loop afterwards caused memory to fill up and the script to fail eventually.
This script will compile rippled, run unit tests and then delete all build
artifacts in many possible configurations (in Linux).
The script will automatically use all available cores to improve compile
speed. All commands are chained via &&, so if any of them fail, the script
will stop at the error.
