Merge pull request #1 from cvmfs/master

pull from upstream cvmfs
Added preliminary support for overlayfs.
Merge branch 'master' of https://github.com/wtsi-hgi/cvmfs into feature/overlayfs
Fixed a bug in cvmfs_listxattr that was causing it to return a null string in the middle of the list of
extended attributes for regular files.
Fixed a bug in cvmfs_listxattr that was causing it to return a null string in the middle of the list of
extended attributes for regular files.
Merge branch 'feature/overlayfs' of https://github.com/wtsi-hgi/cvmfs into feature/overlayfs
Removed 'TEST' from debug log for cvmfs_listxattr
Merge branch 'hotfix/2.1.11-jrandall-listxattr' into develop
Merge branch 'master' of https://github.com/wtsi-hgi/cvmfs into develop
Merge branch 'feature/overlayfs' into feature/ignore-file-fn

Conflicts:
	cvmfs/sync_mediator.cc
	cvmfs/sync_mediator.h
Merge pull request #3 from cvmfs/master

pull from upstream cvmfs
Merge pull request #6 from cvmfs/master

pull from upstream cvmfs
Merge branch 'master' of https://github.com/cvmfs/cvmfs into cvmfs-master-fof

Conflicts:
	cvmfs/cvmfs_server
Merge branch 'feature/overlayfs' into merge-fiff

Conflicts:
	cvmfs/sync_mediator.cc
	cvmfs/sync_mediator.h
Complete implementation of OverlayFS, although the handling of aufs/overlayfs
configuration is somewhat of a hack and also incomplete (it is hard-coded to
overlayfs at the moment in some places).
Merge branch 'master' of https://github.com/wtsi-hgi/cvmfs

Conflicts:
	cvmfs/cvmfs_server
Fixed spelling "mising" -> "missing"
Added configuration options to enable overlayfs (aufs is default in all cases).
in cvmfs_server and swissknife.

e.g. use "cvmfs_server mkfs -f overlayfs" to create a filesystem using overlayfs
Merge branch 'feature/overlayfs' into develop
Merge branch 'develop'

Conflicts:
	cvmfs/cvmfs_server