fix ignore_heartbeat option; refine recv_loop
add recv_loop comment
update setup dependency; use absolute_import
start write_event when conn.send get called
notify user if running on linux but not using gevent ares resolver
set channel accept_watcher highest priority
fix channel greenlet leak bug
add some environ related performance notification
fix __slots__ to reduce memory use
fix Connection.REVBUF
Merge pull request #8 from Catstyle/feature/refine_connection_recv

Feature/refine connection recv