0.06 - 2021-01-26
  - Compiled formulas now access vars via Namespace->get_value
    the same as uncompiled evaluated formulas, though this may be
    internally optimized to the $vars hashref like before if the
    Namespace has not customized get_value.
  - Compiler->output_api now determines whether compiled formula
    take %vars or $namespace as arguments.
  - Deprecated Compiler->variables_via_namespace
  - Parser's scanner_rules have a 4th argument of the variables
    to make available to the code (3rd argument)
  - Fixed a bug in Parser->keyword_map where wrong values could
    get cached between subclass and parent class.
  - Document scanner_rules, keyword_map, etc.
  - Remove dependency on Const::Fast

0.05 - 2020-04-07
  - Parser's scanner_rules can now be overridden in subclasses
  - Added method Namespace->find_methods
  - Work around bug in 5.20 regex parsing on unicode strings

0.04 - 2020-03-22
  - Fix bug where IFERROR would clobber $@
  - Deparse of parse nodes is now handled with method calls,
    making it easier to implement new parse nodes.

0.03 - 2019-05-28
  - Add hexidecimal numbers to Parser grammar
  - Fixed bugs in default namespace functions for perl < 5.16
  - Documentation updates

0.02 - 2019-05-25
  - Fix parser to allow empty function parameter lists
  - Exception objects now stringify to class suffix and message
  - Implemented several more Namespace::Default functions
  - Fixed several perl 5.10 and 5.8 compatibility problems
  - Remove accidental dependencies

0.01 - 2019-05-24
  - Initial release