Clean application of patch - 
- Added --tz-utc to fix issue of dumping timestamp values between 
servers with different global time zone settings, particularly 
with regard to the day of DST changeover, which without this fix,
 would dump duplicate timestamp values.


client/client_priv.h:
  BUG# 13052 - clean application of http://lists.mysql.com/internals/30993
client/mysqldump.c:
  BUG# 13052
  
  Clean application of patch http://lists.mysql.com/internals/30993
  
  - added new --tz-utc option
  - added saving of TIME_ZONE in dump file
  - set TIME_ZONE to "+00:00" in dump
mysql-test/r/mysqldump.result:
  BUG# 13052 New results
mysql-test/t/mysqldump.test:
  BUG# 13052
  
  Added new test to test if the new option --tz-utc places 
  'SET TIME_ZONE="+00:00" at the top of the file and that this fixes 
  the problem of ending up with duplicate timestamp values that should
   be unique on eve of DST