Add a note about the change of default place to look for radsecproxy.conf.

ChangeLog

-2011-04-11 1.6-dev
+2011-04-16 1.6-dev
 	Incompatible changes:
 	- The default shared secret for TLS and DTLS connections change
 	from "mysecret" to "radsec" as per draft-ietf-radext-radsec-12
 	section 2.3 (4).  Please make sure to specify a secret in both
 	client and server blocks to avoid unwanted surprises.
 	(RADSECPROXY-19)
+	- The default place to look for a configuration file has changed
+	from /etc to /usr/local/etc.  Let radsecproxy know where your
+	configuration file by using the `-c' command line option.  Or
+	configure radsecproxy with --sysconfdir=/etc to restore old
+	behaviour.  (RADSECPROXY-31)
 
 	New features:
 	- Improved F-Ticks logging options.  F-Ticks can now be sent to a