[PATCH] Removing "symbol to proc" usage from Active Record

Hi,

I've seen the commits from Aaron Patterson on removing those symbol to proc (.map(&:method)) from the code to speeding up Active Record for a bit. I though it's a good idea, and wish I could help.

So, I've attached the patch which changes all the 'symbol to proc' in active_record/lib to a block. Noted that I've tried to use the variable name which is closest to the context. If it's inappropriate, please let me know

Thank you.