Show HTML entities literally in the output

DoT [intentionally](https://github.com/olado/doT/blob/master/doT.js#L40) does not encode an ampersand if it is a part of HTML entity (btw, why? @olado).

In index.html, event handlers call DoT and apply `String#encodeHTML` afterwards, which annihilates any difference between `{{= }}` and `{{! }}` for the reason described above. As a result, it is impossible to spot any difference between those two in the output.

The patch in question fixes this behavior by encoding ampersands by hand **before** applying `String#encodeHTML`.

P.S. Why all the JavaScript must fit in a (huge) single line?