Add support for g++ to version selection script
Version selection script now compiles versions which are not currently installed
Don't capitalise bash prompt in version selection script
Remove --disable-python and --disable-java flags from configure script
I think it would be useful to have it built with SSL support by default. At the very least, MESOS_CONFIGURE_OPTIONS should be here and be set to SSL options by default, and it should be possible to overwrite it.