recognize "1.0.1e" for openssl libraries
avoid a malloc(0)

This is unlikely to fix any problems, but I think malloc(0) is not
specified by C99.
racket/gui cocoa: fix atomicity of refresh

Atomicity was accidentally turned off in ca0418d47d.

For whatever reason, this bug seems to cause lots of trouble with
32-bit Mac OS X and not as much for 64-bit Mac OS X.