Remove a bunch of unreferenced files

Plus a small number of obsolete packages (like old versions of qemu).

pkgs/applications/misc/fetchmail/security-fix.patch

@@ -1,11 +0,0 @@
---- old/sink.c	(revision 5118)
-+++ new/sink.c	(revision 5119)
-@@ -262,7 +262,7 @@
-     const char *md1 = "MAILER-DAEMON", *md2 = "MAILER-DAEMON@";
- 
-     /* don't bounce in reply to undeliverable bounces */
--    if (!msg->return_path[0] ||
-+    if (!msg || !msg->return_path[0] ||
- 	strcmp(msg->return_path, "<>") == 0 ||
- 	strcasecmp(msg->return_path, md1) == 0 ||
- 	strncasecmp(msg->return_path, md2, strlen(md2)) == 0)