Overhaul how we check for updated template catalog

The goal here was to disable auto-update when compiling Activator, and use the existing cache.properties when we don't auto-update. So Activator will just create cache.properties from hardcoded config.

However, we also had various other problems mostly related to error handling and error reporting. We have some bugs and support issues where things go wrong here so cleaning it all up and adding tons of logging should be useful.