Build mock if not templates

[Andrew Abramov]

If no template need build bundle without bem-xjst core. Instead of it need provide mocks.

This can be useful to build BEMHTML for run in browsers with depsByTech.

For BEMHTML apply method should always returns empty string:

BEMHTML.apply = function () { return ''; };

For BEMTREE apply method should always returns empty object:

BEMTREE.apply = function () { return Vow.resolve({}); };