This patch adds a TOYBOX_SELINUX configuration option to control both the SELinux commands (such as chcon) and the SELinux-specific options to regular commands (such as ls -Z). This lets us #include <selinux/selinux.h> in portability.h. I've also fixed chcon to insist on being given the a context argument. This patch also adds -Z to id and fixes id's regular output (-G should be separated by spaces, non-G output should be separated by commas, and you don't want a double comma where the egid is omitted from the list of groups).

--- a/Config.in	Thu Jan 15 19:09:08 2015 -0600
+++ b/Config.in	Fri Jan 16 13:36:53 2015 -0600
@@ -34,6 +34,13 @@
 
 	  chown root:root toybox; chmod +s toybox
 
+config TOYBOX_SELINUX
+ bool "SELinux support"
+ default n
+ help
+  Include SELinux options in commands such as ls, and add
+  SELinux-specific commands such as chcon.
+
 config TOYBOX_FLOAT
 	bool "Floating point support"
 	default y