netutils/websocket: organizing code

netutils/websocket: organizing code

1. Deleted Unused wqueue function code
2. Added guide line for websocket handler timeout value. It is not supposed
to be 0 becaust it makes busy waiting.
3. Added definition on checking a NULL parameter
4. Changed Inappropriate names:
   websocket_ping_timer() -> websocket_ping_counter()
   websocket_make_block() -> websocket_config_socket()
   WEBSOCKET_SERVER_CHECK_INTERVAL -> WEBSOCKET_ACCEPT_TIMEOUT

Change-Id: I742f5f0a3c6b50252d7a38fe8a10e927b341837a
Signed-off-by: bossjisu <jisuu.kim@samsung.com>