collective/icalendar — pull request #143 by untitaker (2014-07-13 17:08:09+00:00)
Title: Allow dots in property names.

This is for vCard compatibility. From RFC 6350:

The group construct is used to group related properties together.
The group name is a syntactic convention used to indicate that all
property names prefaced with the same group name SHOULD be grouped
together when displayed by an application. It has no other
significance. Implementations that do not understand or support
grouping MAY simply strip off any text before a "." to the left of
the type name and present the types and values as normal.

We could of course consider stripping off the group prefixes, but then that
data would be lost. I recommend we leave this to the user or Component
subclasses to do something meaningful with groups.