Eliminate carriage returns when encoding text

[m1foley]

Fixes issues #9 and #13.

From RFC 6350 section 4.1 ("TEXT"):

A formatted text line break in a text value type MUST be represented as the character sequence backslash (U+005C) followed by a Latin small letter n (U+006E) or a Latin capital letter N (U+004E), that is, "\n" or "\N".

@brendon, can you review & make sure this solves the problem you first reported?

[qoobaa]

Merged. Thanks a lot.

[brendon]

Hi @m1foley, that did the trick. Thanks heaps for looking into that for me. Your solution is a lot more succinct!

For some reason @qoobaa, my add_role change hasn't come through into the gem. Are you able to check this out?

[brendon]

#15