Merge tag 'v4.1.15' into zygo-4.1.15-zb64

This is the 4.1.15 stable release

# gpg: Signature made Tue Dec 15 00:24:57 2015 EST using RSA key ID 6092693E
# gpg: Good signature from "Greg Kroah-Hartman (Linux kernel stable release signing key) <greg@kroah.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 647F 2865 4894 E3BD 4571  99BE 38DB BDC8 6092 693E