* Added code optimization to reduce sequential appends of static text.
* The default symbol in dynamic attributes is now symbolic.
* The built-in attrs dictionary of static element attributes now correctly
works with tal:define, etc.
* Fix slice code generation compatibility issue on Python 3.9.
* Expose default marker as importable symbol chameleon.tales.DEFAULT_MARKER.
* Removed legacy flag literal_false. To get a similar behavior, use boolean_attributes.
OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-Chameleon?expand=0&rev=35