ArrayRef handler can read JSON
Documentation for Handler::ArrayRef

And a few bugfixes and test changes.
First version of Positron::Template, tests run
Moved from Environment::get to Expression::evaluate

This allows more complex expressions; added some in tests.
Bugfix: remove structure sigils on copy, not original

They were being removed from the original DOM nodes, which meant that those
could not be reused!
Switch statement for Positron::Template
Replaced inline structure sigil finder with sub call
Positron::Template: structure comments
File includes for Positron::Template
Preparations for a release with Positron::Template
Release v0.1.0

  Positron::Template:
  - First running version of Positron::Template
  - Use ArrayRef handler for now; others are not implemented
  - Supported sigils:
    text replacement, loops, conditions, switches, comments (text and structure),
    file includes
  Positron::Handler::ArrayRef:
  - Handler can optionally read JSON, not just storable