Changelog for ginger2-2.1.0.1

2.0.0.0 - Initial release 2.1.0.0 - Improved documentation. - Added support for `{% elif %}`. - Fixed some spurious test failures. - Moved `date` builtin to ginger extensions (its alias, `dateformat`, was an extension already). - Added built-ins: - random() - min() - max() - sum() - reject() - Added some built-in string, dict, and list methods - Made truthiness checks more lenient, so that things like `{% if [] %}` work like in Jinja. - Added an RNG state to the execution environment; this is necessary in order to support the random() function.