OSR-29
    OSR-31
    OSR-33
    Added support for yy-mm-dd format (OSR-31)
    Modified read.table to take into account optional
    parameters (as.is, colClasses, staringsAsFactors) (OSR-29)
    Modified parse_regex to use lists with named elements, rather
    than parallel vectors. (OSR-33)

    Added support for optional tz (timezone) argument to
    as.POSIXct.character (OSR-39)

    Also, for compliance with other implements of as.POSIXct.*,
    removed the format argument. Another method with this argument
    was created, called string.to.POSIXct.