add list() method to base methods on ModelEndpoint. Add allowed_methods decorator to decorators
improve README
add documentation for list()
oops. forgot to delete my original attempt at methods_allowed
update BaseEndpoint.list() to output records in the same format as encoders.cencode
r488264: use encoder.encode instead of serializers.serialize
r488268, use args instead of kwargs
update docs
Updates for code review.

- Allow for max_per_page to be endpoint specific.
- Invalid page numbers return empty lists (so you know when you're at the end)
- Tests for the list method.
Merge branch 'master' into toast38coza-add_list_as_base_method

Conflicts:
	ajax/decorators.py
	ajax/endpoints.py
	tests/example/endpoints.py