Replaced many core.system with core.check_system commands and added a few comments
Replaced many core.system with core.check_system commands and added a few comments

git-svn-id: c36fc656d29f06fca4500ebb6a8d6f432478a0b6@16800 4e558342-562e-0410-864c-e07659590f8c

efajardo/osg-test,efajardo/osg-test