Fix #33 newlines and escape chars formatting and parsing

[iammatis]

According to section 3.3.11 of the RFC 5545 TEXT property can contain characters that need to be escaped.

An intentional formatted text line break MUST only be included in a "TEXT" property value by representing the line break with the character sequence of BACKSLASH, followed by a LATIN SMALL LETTER N or a LATIN CAPITAL LETTER N, that is "\n" or "\N".

The "TEXT" property values may also contain special characters that are used to signify delimiters, such as a COMMA character for lists of values or a SEMICOLON character for structured values. In order to support the inclusion of these special characters in "TEXT" property values, they MUST be escaped with a BACKSLASH character. A BACKSLASH character in a "TEXT" property value MUST be escaped with another BACKSLASH character. A COMMA character in a "TEXT" property value MUST be escaped with a BACKSLASH character. A SEMICOLON character in a "TEXT" property value MUST be escaped with a BACKSLASH character. However, a COLON character in a "TEXT" property value SHALL NOT be escaped with a BACKSLASH character.

This PR attempts to fix an issue where such characters where not correctly parsed nor formatted.

[iammatis]

Also should fix #27