Change of version info to '1.0rc2' vs '1.0dev' due to build from git

First thanks for all your efforts on gevent - an incredible library.

With the build now direct from git (pip install cython -e git://github.com/surfly/gevent.git@1.0rc2#egg=gevent), it was installing the version in pip as gevent==1.0dev rather than gevent==1.0rc2.

All the best,
Dan