Fix a compiler warning when checking for arc4random_buf linker breakage.

Patch by Ralph Castain.
Merge remote-tracking branch 'origin/patches-2.0'

Conflicts:
	evutil_rand.c
Fix another arc4random_buf-related warning
Merge remote-tracking branch 'origin/patches-2.0'
add a http default content type option
regress_main: logging all if env EVENT_DEBUG_LOGGING_ALL isset
Merge pull request #80 from azat/tests-add-event-debug-logging-all

regress_main: logging all if env EVENT_DEBUG_LOGGING_ALL isset
Merge remote-tracking branch 'origin/pr/79'
Tweak indentation
http: implement new evhttp_connection_get_addr() api.

Basically tcp final handshake looks like this:
    (C - client, S - server)
    ACK[C] - FIN/ACK[S] - FIN/ACK[S] - ACK [C]

However there are servers, that didn't close connection like this,
while it is still _considered_ as valid, and using libevent http layer
we can do requests to such servers.

Modified handshake:
    (C - client, S - server)
    ACK[C] - RST/ACK[S] - RST/ACK[S]

And in this case we can't extract IP address from socket, because it is
already closed, and getpeername() will return: "transport endpoint is not connected".
So we need to store address that we are connecting to, after we know it,
and that is what this patch do.

I have reproduced it, however it have some extra packages.
(I will try to fix it)
https://github.com/azat/nfq-examples/blob/master/nfqnl_rst_fin.c
regress_http: add tests for evhttp_connection_get_addr()
Merge branch 'pr_81'
Avoid redundant invocations of init_extension_functions for IOCP
Merge remote-tracking branch 'origin/patches-2.0'
Small doxygen tweaks
Try another doxygen tweak
update the 2.0 changelog
Merge remote-tracking branch 'origin/patches-2.0'
start writing a changelog for 2.1.4-(beta?)
bug fix for issues #293 evdns_base_load_hosts doesn't remove outdated adresses

As mentioned at https://sourceforge.net/p/levent/bugs/293/
 created a small function "evdns_base_flush_outdated_host_addresses" which removes all the previous requests of hosts , if user wants to clean up the list of hosts can call and use this function. 
Requires function declaration to be added in include/event2/dns.h
 Adding it in another patch for the same bug.