Buildroot 2018-11 (#258)

* Update to buildroot 2018.11

* containerd update

* runc update

* runc docker engine

* runc docker proxy

* update rpi firmware

* update network manager

* update dhcpd

* update wait on network

* update rpi wifi

* revert glibc

buildroot/docs/manual/developers.txt

@@ -31,7 +31,8 @@ the +DEVELOPERS+ file for various tasks:
 
 - When passing one or several patches as command line argument,
   +get-developer+ will return the appropriate +git send-email+
-  command.
+  command. If the +-e+ option is passed, only the email addresses are
+  printed in a format suitable for +git send-email --cc-cmd+.
 
 - When using the +-a <arch>+ command line option, +get-developer+ will
   return the list of developers in charge of the given architecture.