changes rolled up for node 0.10.0

Took a couple of the other pull requests, and fleshed them out.  Add compile options for the Mac, but they are untested.  This set was tested on a CentOS 5.1 32-bit machine.

Updated the Readme, as well :-)

I am using this to try and debug a long-running process that uses node-db-mysql and node-genx.  One of them appears to be segfaulting under 0.10.0, and I am hoping this helps me find out which.