Add preinstall script to erase Eclipse prior to install.

Otherwise, there is a link in the folder that causes some kind of
recursive installation.
Update minimum autopkg version.

All recipes rely on a JSSImporter which requires 0.4.0, so the recipes
should have that as a minimum as well.
Update/move Keynote. Update README.
Add in icons. Finish updating AppStoreApps, and moving.
Update managed software list.
Fix Geogebra recipe with preinstall script.

The Geogebra package ID changed. This causes the installer to assume
that pre-existing installations are not the same app, and thus does not
overwrite, but instead makes a new Geogebra subfolder to install into at
/Applications/Geogebra/Geogebra.app.