Entry types are now in their own classes

Other changes:
- Added a plain select entry type
- Added (untested!) support for custom entry types
- Bug fix for text-entry defaults
- Added the start of an event registry / observer pattern (just a new item event for now)
- Attached the error handler to all ajax calls
- Set a pattern for the context on ajax calls (self: this, call: "theMethodName", etc: "etc")
- Set a "call-for" pattern, in preparation for backend classes
- Added a wrapper for console.log as a class-level method, and added an object-level method to call it
- Temporary workaround so I can test the examples without a connection