#198420  Make sure internal field and widget names are truncated to 32 characters to match the database values.

Move field.php to an 'examples' folder, since it isn't part of the code. Also add a simpler example that creates a complete form element when called by hook_widget(), similar to the way the older code works. This simple example doesn't use hook_elements(), and thus does not create re-usable widgets as the core field modules do.