Merge infrastructure for SASL authentication support from flashback.

This includes all of the underlying support, but doesn't hook it up to the
/SERVER command yet, so it's not useable at this point.


git-svn-id: svn://svn.code.sf.net/p/bitchx/code/trunk@216 13b04d17-f746-0410-82c6-800466cd88b0

include/ircaux.h

@@ -134,6 +134,7 @@ char *	get_userhost		(void);
 
 char *	urlencode		(const char *);
 char *	urldecode		(char *);
+char *	base64_encode	(const void *data, size_t size);
 
 /* From words.c */
 #define SOS -32767