Escaped dot in `rname` handled as normal dot

[Jens Spanier]

For the rname in a SOA record it's possible to escape a dot.

So john\.doe.example.com should become [e-mail]. See here.

But the result is just john.doe.example.com and therefore it's not possible to finde the right . to replace it with an @.

[M4t7e]

@JensSpanier I created #93 that should fix the problem.