pywsgi: set max_accept to 1 if environ['wsgi.multiprocess'] is true (e.g. in case of gunicorn having >1 workers)

add DEFAULT_MAX_ACCEPT to server.py: StreamServer.max_accept is now None and set to DEFAULT_MAX_ACCEPT before starting listening

add __nonzero__ for Greenlet: now Greenlet is true when it was started even if it was not switched to yet.

rename handle_error's argument "where" to "context"

use "%s failed with %s" message instead of "Ingoring..."; this is compatible with gevent 0.13

cython 0.15 dead code detection did remove the call to ENDIF()
resulting in broken C code.

temporarily disable EV_CHILD since it breaks Python's subprocess and os.waitpid because of child reaping

also make sleep(negative) equivalent to sleep(0); raising an error really has no use here;

- it now avoids unnecessary blocking and returns the results asap
- changed argument order of internal class IMapUnordered.
- new internal class IMap added to pool.py

add green version of getfqdn() to socket; add socket.__dns__ which lists all dns functions (for monkey)