add "enet_host_destroy"?

[Ayyyg]

http://enet.bespin.org/group__host.html#gacec1e9a0b528c1f9ce30544d2d5b5b79

this library works great but it lack a function to destroy a host completely

for example. if you are a client, you disconnect from server but the client actually still running in other thread

if you are a server, you need to exit application or it still running in other thread, too

and just a suggestion, add a check when calling Peers[val_int(ID)] ? so that if you set a non exist peer ID, it won't crash application