New function is_package_installed(). Changed copyright yeart to 2011.
New function is_package_installed().
Changed copyright yeart to 2011.

FelixZhang00/rudix,FelixZhang00/rudix,rudix-mac/rudix,FelixZhang00/rudix,rudix-mac/rudix,rudix-mac/rudix,FelixZhang00/rudix