set thread name for epoll worker thread, so that we can observe the c…

[0xhellord]

set thread name for epoll worker thread, so that we can observe the cpu usage of every worker thread easily in top -H -p $pid.

[ldcsaa]

fixed at the dev branch, HP-Socket worker threads would set a unique thread name.

Other threads like Linux/src/common/Thread.h, should set thread name by user self. For example invoke pthread_setname_np() at the entry of user thread proc.