B"H make sure to close sockets when finished
B"H net_io.c: revert previous change and advertise HTTP 1.1

It seems server code should be compatible with HTTP 1.1; the features
unique to 1.1 mostly are upon the client to support, and some headers
used (for example Cache-Control) may need 1.1.
Merge branch 'master' of https://www.github.com/MalcolmRobb/dump1090 into socket_hang
B"H Merge branch 'master' of https://www.github.com/MalcolmRobb/dump1090 into socket_hang

Conflicts:
	net_io.c
Merge branch 'master' of https://www.github.com/MalcolmRobb/dump1090 into socket_hang
Merge pull request #33 from hhm0/socket_hang

Close network file descriptors when finished with them
Merge branch 'master' of https://www.github.com/MalcolmRobb/dump1090 into http_server_wk