Deprecates get_userinfo() master function.

get_userinfo() function has a very ill-defined interface.
It returns an array which is usually accessed by the
*internal* symbolic constants (for indexing the
*internal* userlist structure) from userinfo.h plus an
offset. This is error-prone and the internal indices
can therefore never be changed internally.
It is also completely undocumented.

The alternative is query_userlist(). If a lot of
people need all data from the userlist at once,
an additional query function should be designed.

Change-Id: I848b764f46f609f612d1847c1e0198cd3dc454ab
diff --git a/secure/master/userinfo.c b/secure/master/userinfo.c
index fba781f..bde7788 100644
--- a/secure/master/userinfo.c
+++ b/secure/master/userinfo.c
@@ -450,7 +450,7 @@
 }
 
 // Daten aus der Userlist fuer diesen User liefern. Macht ggf. find_userinfo()
-public mixed *get_userinfo(string user) {
+public deprecated mixed *get_userinfo(string user) {
   if(!user||user=="")
     return 0;
   user=explode(user,".")[0];