Add Transport:sendfile/4,/5

Adds offset based sendfile to transports. Same behaviour as
file:sendfile/4,/5 except socket and file arguments are reversed and
either a raw file or a filename can be used.

sendfile/2,/4,/5 now compulsory callbacks in ranch_transport.

ranch_tcp:sendfile/2 now defaults to a chunk_size of 8191 - the default
for ranch_ssl:sendfile/2. The same default is used for both
ranch_tcp:sendfile/4,5 and ranch_ssl:sendfile/4,5.
Report errors when connection processes fail
Fix an example in the guide
Update erlang.mk
Update Ranch to 0.8.5
Merge branch 'add-offset-sendfile' of git://github.com/fishcakez/ranch
Close the socket if no child process was started
Print an error if the supervisor receives an unexpected message
Don't report error when protocol exits with reason shutdown

Exiting with reason `shutdown` or `{shutdown, term()}` is not an error.
Include protocol module in error report when connection fails
Merge branch 'no-shutdown-report' of git://github.com/fishcakez/ranch
Use previous ecc workaround for R16B02 as well

The implementation of elliptic-curve ciphers that has been introduced in
R16B01 is still incomplete (and broken).  This makes our previous
workaround (see c0c09a1311) work for R16B02 as well.
Add hibernate_after ssl option
Merge branch 'broken-ecc-workaround-R16B02' of git://github.com/KlausTrainer/ranch
Merge branch 'hibernate_after' of git://github.com/talko/ranch
Implements ranch_transport:connect/4.

Adds a transport connect method that takes a timeout, with implementations for both ssl and tcp connections.
Fix a socket leak with SSL when ssl_accept fails
Flush any message acceptors may receive and log them

Inspired by what supervisor does.
Update Ranch to 0.9.0
Update the link to the guide