WL#1580: --start-datetime, --stop-datetime, --start-position (alias for --position) and --stop-position
options for mysqlbinlog, with a test file.
This enables user to say "recover my database to how it was this morning at 10:30"
(mysqlbinlog "--stop-datetime=2003-07-29 10:30:00").
Using time functions into client/ made me move them out of sql/ into sql-common/.
+ (small) fix for BUG#4507 "mysqlbinlog --read-from-remote-server sometimes
cannot accept 2 binlogs" (that is, on command line).


client/client_priv.h:
  new options for mysqlbinlog
client/mysqlbinlog.cc:
  WL#1580: --start-datetime, --stop-datetime, --start-position (alias for --position) and --stop-position.
  (small) fix for BUG#4507 "mysqlbinlog --read-from-remote-server sometimes
   cannot accept 2 binlogs".
include/my_time.h:
  importing time functions so that client/ files can use them.
include/mysql_time.h:
  importing time types so that client/ files can use them.
sql-common/my_time.c:
  importing time functions so that client/ files can use them.
sql/mysql_priv.h:
  moving time functions out of sql/ into sql-common/
sql/time.cc:
  moving time functions out of sql/ into sql-common/
sql/tztime.h:
  moving time functions out of sql/ into sql-common/