[ref] tests/event.py
[ref] tests/parse.py
[ref] tests/unflod_lines.py
[ref] tests/contentline.py
[ref] tests/eventlist.py
[ref] tests/calendar.py
[ref] tests/component.py
[add] parse_duration method (event duration property). Looks like C, but garanteed O(n) execution time.
[ref] Use individual test files
[fix] pep8: no trailing \s
[fix] A DURATION property cannot contain more than 1 occurence of each time unit
[fix] No string overflow