Bulk update support

No tests, no documentation updates, just the method. Tested both simple and upsert update from within my framework, so this should be good to run, but of course you will want proper tests I'm sure.

First question is if you want this at all (I guess the reason why this isn't in the library already is that bulk updating is fairly new). And then if someone from your side would have the time to add tests etc.? I simply can't be sure I could spend more time on this.

Cheers,
Martin