added max chunk check on recv

[seanmcevoy]

this fix allows yaws to receive data over 64MB in size.
open an erlang shell, start a tcp listener, send 256M + 1B and connect to it with:

spawn(fun() ->
{ok,LS} = gen_tcp:listen(3456,[{reuseaddr, true}, {active, false}, binary]),
{ok,SS} = gen_tcp:accept(LS),
gen_tcp:send(SS,crypto:strong_rand_bytes((4 * 64 * 1024 * 1024) + 1)),
receive stop -> ok end
end).
{ok,RS} = gen_tcp:connect("localhost",3456,[{reuseaddr, true}, {active, false}, binary]).

then on the receive side note that this can only be consumed in chunks of 64MB or less:
gen_tcp:recv(SS, (64 * 1024 * 1024) + 0, 1000).
gen_tcp:recv(SS, (64 * 1024 * 1024) + 1, 1000).
gen_tcp:recv(RS, (64 * 1024 * 1024) + 0, 1000).
gen_tcp:recv(RS, (64 * 1024 * 1024) + 1, 1000).
gen_tcp:recv(RS, (64 * 1024 * 1024) + 0, 1000).
gen_tcp:recv(RS, (64 * 1024 * 1024) + 1, 1000).
gen_tcp:recv(RS, (64 * 1024 * 1024) + 0, 1000).
gen_tcp:recv(RS, (64 * 1024 * 1024) + 1, 1000).
gen_tcp:recv(RS, 1, 1000).

in our application all uploads of files greater than 64MB fail with enomem in the same way as demonstrated here.
this change works in our application at least.

[avtobiff]

Thanks for your PR!

Please add a test for the new behaviour.

Please write a longer commit message describing the change.
(Parts of the PR's description are good candidates of info
describing the reason and method for the change.)