Node support for Tor hidden services

This commit adds support for .onion addresses (mapped into the IPv6
by using OnionCat's range and encoding), and the ability to connect
to them via a SOCKS5 proxy.

src/util.cpp

@@ -704,7 +704,7 @@ string DecodeBase64(const string& str)
 
 string EncodeBase32(const unsigned char* pch, size_t len)
 {
-    static const char *pbase32 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+    static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
 
     string strRet="";
     strRet.reserve((len+4)/5*8);