• An asynchronous API is now available, and async filters, extensions, and
  loaders is supported. The async API is optional and if you don't do
  anything async (the default), nothing changes for you. You can read
  more about this
  here. (fixes #41)
• Much simpler higher-level API for initiating/configuring nunjucks is
  available. Read more
  here.
• An official grunt plugin is available for precompiling templates: grunt-nunjucks
• The browser files have been renamed. nunjucks.js is now the full
  library with compiler, and nunjucks-slim.js is the small version
  that only works with precompiled templates
• urlencode filter has been added
• The express integration has been refactored and isn't a kludge
  anymore. Should avoid some bugs and be more future-proof;
• The order in which variables are lookup up in the context and frame
  lookup has been reversed. It will now look in the frame first, and
  then the context. This means that if a for loop introduces a new
  var, like {% for name in names %}, and if you have name in the
  context as well, it will properly reference name from the for loop
  inside the loop. (fixes #122 and #119)