Merge test cases from MySQL into Drizzle infrastructure

From Brian:
From time to time we have been pulling bug test cases from MySQL as they are being added (aka... we grab any bug test cases and add them to our regression suite). If anyone is up for a task, it would be cool to find all of the relevant bug test cases that have been added in the last 1.5 years to MySQL 5.1 that are relevant to us, and add those test cases (and register bugs if need be).

Speaking of bugs, we haven't fully embraced this but I think we should be adding all bug regressions to a "regression" test suite and name them after their bug number. We aren't fully doing this right now, but I think it would be a sharp thing to do. Long term I am hoping that this sort of pattern would encourage advanced users to push test cases into bzr that we can then use directly.