update to 3.15.3 Linux kernel
add retry to kernel curl, my net was up and down like mad
change the build instructions to be more like what I actually do
the 3.15.3 .config we built with
Merge pull request #419 from SvenDowideit/update-to-3.15.3-linux-kernel

Update to 3.15.3 linux kernel
Add util-linux for nsenter
Add -no-pad not to pad output