Declare these test methods.
Need a cast here, since NSString types C strings as const char *, and ours is const unichar *.
Added a property by which you can request a time zone separator. Proposed by @danielctull, although this is a different implementation that lets you specify any character.
Added a failing test case for parsing a date with a(n unusual) time zone separator.
Fix parsing dates with custom time-zone separators.