Merge branch 'dev_2.x'

update version to 2.2.0

Merge branch 'mempool_thp' into dev_2.x

update memory pool thp, prefetch ptr datas in muggle_memory_pool_ensure_space

memory pool support THP(Transparent Huge Pages)

fix unittest event fd, init socket lib

add unittest event_fd

update unittest event context

update unittest array_list

update coverage option and update unittest_str

add comment for muggle_event_strerror

Merge branch 'dev_2.x'

update version to 2.1.4

use muggle_wait_tcp_connect in muggle_tcp_binded_socket_connect

Merge branch 'dev_2.x'