Added option --lock-directory so that you can now syncronize several mysqlslap processes across several machines. Not perfect yet.

Added --slave option if you are trying to syncronize around one server using the lock-directory option plus NFS. 

Added options to allow you to run several concurrency runs in one call. aka --concurrency="1, 8, 64, 128"

Time collection is now done in a finer grain manner, and is linked to the sync call (doesn't count the cost of the blocked processes that are setup to run).



client/Makefile.am:
  Adding my_lock compile bits so we can have locking.
client/client_priv.h:
  New options for lock directory, number of query, number of rows and slave status.
client/mysqlslap.c:
  Updates for lock-directory.
  Simplified fork() code that is called. It should be possible to build now a version that used threads if someone wanted to port to windows).
  You can now specify several concurrency runs in one pass of the code.