Recoded the addons tab with new look and better information about the
installed addons
changed version number and updated changelog
added refresh button for addons
fixed the addons table generator so that it lists up to 4 addons per
row. also renamed launch_addon to addon_handler as it now handles
anything clicked on the addons tab
updated changelog with final changes before release
Merge remote-tracking branch 'origin/development' into bleeding-edge