#79 Resources property bug with commas

[Antony]

The RESOURCES property has the same bug that CATEGORIES had, i.e. it escapes the commas, e.g.

icalcomponent_add_property(event, icalproperty_new_resources("a,b,c"));

results in

RESOURCES:a\,b\,c

Looks like the general suppor for TEXT attributes is flawed as it does not support comma separated values because it either escapes them (RESOURCES) or with the CATEGORIES patch, will not support values containing commas.