Cleaned up memory allocation to be a little more staight forward (though I suspect someone will hate my sizeof() increment). 
Nothing really to see here. Updated comments in code.

More comments are probably needed, but isn't that always the case?


client/mysqlslap.c:
  Updated docs. 
  Removed complicated malloc calls with a single malloc. Cleaned up the way statements were be free'd (aka its now a function instead of a bunch of copy/paste).
  Removed older and not so accurate timediff() call. Cleaned up call to parse out concurrency.
mysql-test/t/mysqlslap.test:
  Edited the tests to make sure we check default concurrency (we can't test concurrency normally since in theory the results could be random).
  You will noticed that the result was not changed.