v0.1.4

Added

• Loader(sandbox=True) for untrusted templates: only engines with
  SANDBOXED = True take part (Jinja through SandboxedEnvironment, Liquid,
  Mustache, Handlebars, Go through a gotpl SandboxPolicy, shell, envsubst,
  copy); a file another engine claims raises SandboxError before it is read.
  A sandboxed template sees plain data: no method of the caller's objects, and
  a value that is not a plain type as its text.
• tplx.evaluate and Loader.evaluate: an expression's value, its type kept,
  in Python (DEFAULT_ENGINE, refused by a sandbox) or an engine's syntax
  (engine="jinja", ".liquid", "go", ...), through Template.evaluate.
• Loader.compile, cached; Template.references(), the names a template
  reads.

Full Changelog: v0.1.3...v0.1.4