Rewrote project to version 2.0.0.

- Fixed escaping inside strings and added more checks

- Dropped the requirement for closing curly braces inside interpolated
  sections to be escaped with a backslash by checking JavaScript syntax

- Added more errors and warnings

- Changed for loops’ syntax to use “of” instead of “in” for consistency
  with changes to ECMAScript

- Made output variable dodge user variables (the same doesn’t apply to
  other variables yet, however)

- Made it more difficult to accidentally interfere with Razor Leaf;
  esprima might be pulled in to handle multi-line comments

- Changed block and template names to whitespace-free identifiers

- Made it possible to use spaces for indentation
  (as much as it pains me)

- Added a built-in template loader for convenience

- Changed variable declarations to happen at the time of their use,
  making it possible to use recursive functions

- Cleaned up the parser and compiler; the transformer for include still
  needs to be moved into parser code