Gratuitous string concatenation occurs when escaped curly braces are present

The output is less than ideal when \{ and \} are present -- there is additional string concatenation going on in the compiled function that is pretty ugly:

Template:

\{\{Outer with data\}\} {{data.name}}

<code>
  \{\{Nested\}\}
</code>

<code>
  \{\{Nested with data\}\} {{data.name}}
</code>

Output:

(function anonymous(data_0) {
  var frag = document.createDocumentFragment();
  var data = data_0;
  var el0 = document.createTextNode("{"+"{"+"Outer with data"+"}"+"}"+" "+data_0["name"]+"\n\n");
  frag.appendChild(el0);
  var el1 = document.createElement("code");
  el1.textContent = "\n  "+"{"+"{"+"Nested"+"}"+"}"+"\n";
  frag.appendChild(el1);
  var el2 = document.createTextNode("\n\n");
  frag.appendChild(el2);
  var el3 = document.createElement("code");
  el3.textContent = "\n  "+"{"+"{"+"Nested with data"+"}"+"}"+" "+data_0["name"]+"\n";
  frag.appendChild(el3);
  return frag;
})

The parser could be modified to concatenate the braces into an existing content block instead of creating a new one, or DOMly could be fixed to combine content blocks into a single string instead of concatenating multiple strings.

This is due to the fixes for #7. @cif

Start by tracing the parser and DOMly content-block handling affected by the fixes for #7; the issue does not name specific files or tests. Use the provided escaped-brace template and compiled output as the regression case, and consider both suggested implementation areas. Done means the generated function avoids gratuitous string concatenation while preserving the escaped braces and interpolated data.