- test tzoffset
    - make more tests (see Devel::Cover)
    - clean up xs
    - allow cdate() to print as different formats
    - Document format flags that don't work everywhere (see comments in *.t files)
    - Every "return 0" in the strptime case statement in Piece.xs needs to be preceded by a useful error statement
    - _C_time_locale should only get populated when really needed
    - use macros or something to get all the strlen stuff out of xs hash fetches
    - make sure changing class vars effects all instances 
    - add better %V support, newer versions of libc seem to have it: 
            https://opensource.apple.com/source/Libc/Libc-1158.20.4/stdtime/FreeBSD/strptime.c.auto.html