The Renderer class's default loader now inherits the decode_errors
attribute for the instance.

The Renderer class now accepts a loader implementing get()
(e.g. a dictionary or Loader instance) rather than a load_template
function.

Doctests now pass, and they pass running "nosetests --with-doctest".

Apparently, nosetests runs doctests without the doctest.ELLIPSIS
option enabled.  This caused the Modifiers.set() test to fail.

Multiline comments now permitted.  Fix courtesy of fczuardi.

  See https://github.com/defunkt/pystache/issues/33

Ensures that the Renderer class can handle the case of load_template
not returning unicode.