linux: Don't put the kernel version in meta
Unify the Linux kernel configurations

Having N different copies of the NixOS kernel configuration is bad
because these copies tend to diverge.  For instance, our 3.10 config
lacked some modules that were enabled in older configs, probably
because the 3.10 config had been copied off an earlier version of some
older kernel config.

So now there is a single kernel config in common-config.nix.  It has a
few conditionals to deal with new/removed kernel options, but
otherwise it's pretty straightforward.

Also, a lot of cut&paste boilerplate between the kernel Nix
expressions is gone (such as preConfigure).
iwlwifi4965ucodeV1: Remove

This is verrrry obsolete.
linux: Disable /dev/kmem

See e.g.
  https://wiki.ubuntu.com/Security/Features#A.2BAC8-dev.2BAC8-kmem_disabled
linux: Remove some unused patches
linux: Remove CIFS timeout patch

We longer use CIFS in the VM tests so we don't need this anymore.
linux: Remove obsolete AUFS 3.7 patch
Style fix
linux: Enable stack protector

This may prevent exploitation of buffer overflows.
linux: Enable detection of hung tasks
linux: Include "NixOS" in "uname -v"