Sanitize comments

[nippur72]

The following is valid template code

<div>
   <!-- /* hello */ -->
</div>

but won't compile because the /* */ cause problems due to comment text being embedded as-is in the output:

  2:4  error  Unexpected token *

✖ 1 message (1 error, 0 warnings, 0 infos)

I suggest to sanitize the text against /* and */.