libev: change test-client and test-server to set info->event for -e

Signed-off-by: Alejandro Mery <amery@geeks.cl>
alloc: make _lws_realloc static

Signed-off-by: Alejandro Mery <amery@geeks.cl>
libev: also select libev if the LWS_SERVER_OPTION_LIBEV flag is set

Signed-off-by: Alejandro Mery <amery@geeks.cl>
context: unify libwebsocket_create_context()'s return

Signed-off-by: Alejandro Mery <amery@geeks.cl>