patch applied (packages/time): Changed %Z to produce the time zone offset if the time zone name is " " .

[bjorn at bringert.net]

Sun Feb 11 10:11:09 PST 2007  bjorn at bringert.net
  * Changed %Z to produce the time zone offset if the time zone name is "".
  Rationale: Without this, if you format a ZonedTime which contains an 
  unnamed timezone, %Z produces the empty string. This is invalid in 
  many formats. It is better to output the offset when there 
  is no timezone name.

    M ./Data/Time/LocalTime/Format.hs -1 +3
    M ./Data/Time/LocalTime/Parse.hs -7 +10