Semicolons in values

[untitaker]

I realize that icalendar is not supposed to be used for parsing VCARDs, but i do it anyway because the alternative libraries don't seem to be very well maintained (i use the Collection class directly for this). It is no surprise that it does not do what i want:

# variable text
ADR;TYPE=POSTAL:;2822 Email HQ;Suite 2821;RFCVille;PA;1521$;USA

# Component.from_ical(text).to_ical(text)
ADR;TYPE=POSTAL:\;2822 Email HQ\;Suite 2821\;RFCVille\;PA\;1521$\;USA

It seems that subclasses of Collection seem to be able to set special attributes such as required, singletons etc to influence the parsing behavior. I propose such a new attribute which keeps icalendar's parser from escaping semicolons in certain values.