Support a few more socket options, and refactor the option setting a bit. (Patch from the Google tree.)

Make the query callbacks return the number of timeouts that happened during the execution of a query, and update documentation accordingly. (Patch from the Google tree.)

Three fixes in one commit (sorry): a) Take care of the tcpbuf if it ends while queued for transmission, note broken servers and close them in the main loop, and store TCP socket generation number in order not to send the same query twice over the same socket.

is non-NULL before we FD_CLR

both to occur

several functions (write_tcp_data, read_tcp_data, read_udp_packets) so that
if it fails and the socket is closed the following code doesn't try to use
the file descriptor.

TCP is used since there are several edge cases where it still makes sense.

something with the ares_save_options() where it would try to do a malloc(0)
when no options of that type needed to be saved.  On most platforms, this was
fine because malloc(0) doesn't actually return NULL, but on AIX it does, so
ares_save_options would return ARES_ENOMEM.

although the check for HAVE_STRUCT_TIMEVAL solved the redefine it is incorrect; lets see if a check for HAVE_GETTIMEOFDAY also works; if gettimeofday() is present then we can assume we have the timezone struct too.

sync'd with lib makefile changes: use var for awk; fixed RECV* / SEND* defines; debug var can be overwritten; added better compiler path handling.

one name... Reported by James Bursa

gcc 4.2.0 warning: -Waddress

He also made recent Microsoft compilers use _strdup() instead of strdup().

/etc/hosts file. Patch edited for coding style and functionality by me
(Daniel).

from it in randomize_key()

used to keep options for later re-usal when ares_init_options() is used.

specific sockets and thus avoiding select() and associated functions/macros.
This function will be used by upcoming libcurl releases for this very
reason. It also made me export the ares_socket_t type in the public ares.h
header file, since ares_process_fd() uses that type for two of the arguments.