added requirements section

Changes.md

@@ -2,7 +2,8 @@
 		- fixed some short tags in example.php,
 		  fixed queries to .net whois server,
 		  added support for .pe domains,
-		  fixed .se registration detection
+		  fixed .se registration detection,
+		  added requirements section in README
 		  thanx to Speedywise
 
 2005/10/09  Released phpWhois 4.0.1

Readme.md

@@ -22,6 +22,15 @@ AS (Autonomus System) handle instead of the domain name. Limited,
 non-recursive support for Referral Whois (RFC 1714/2167) is also
 provided.
 
+Requirements
+------------
+
+phpWhois requires PHP 4.3.0 or better with OpenSSL support to
+work properly. Without SSL support you will not be able to
+query domains which do not have a whois server but that have
+a https based whois. Also, you can run it in lower PHP versions
+but without timeout control (see example.whois)
+
 Installation
 ------------