Merge pull request #17 from proxyio/dev

Optimize ev_signal/ev_unsignal operations
[feature] set env_max_process by env
[feature] ev_get_loop_lla
[feature] add tools/lat for c
[feature] fix for old version of build toolchains
[feature] multi sender
[feature] fix counter
[feature] latence perf
[feature] latence perf
[feature] fix compiler warning
[feature] docs
[feature] docs
[feature] fix pubsub test
[feature] add ppt file
[feature] up docs
[feature] thr perf
Merge branch 'master', remote branch 'origin' into dev
[feature] fix perf