build: Checking only major release of redhat

Redhat & centos are releasing distro following the major.minor model.
We where checking both of them when setting up a role. In fact, all
major releases are compatible and we should not break if an update (6.4
-> 6.5) occurs.
base.install: Upgrading default redhat to 6.5

Since 6.5 is released, let's use it as default
build: Checking only major release of redhat (bis)

Some roles didn't got updated during the last commit.
common: Do not mount /dev/ in bind mode

When /dev is let unmounted, like under kill -9 or an untrapped event, we
are in a situation where the /dev is leaved as mounted in the chroot.

When another job is coming to clear it, the /dev of the host is damaged.

This patch simply copy the content of the /dev/ in chroot's /dev.
As we have only special files, this is not an issue and no more risk to
kill the /dev's host.
common: Don't keep /dev inside the final tree

There is no need to keep /dev inside the final tree since it will be
constructed at boot time.
common: Excluding /dev/shm from rsync

This directory could be big.
common: Prevent ctrl-c during cleanup()

Cleanup is a peace of code that should not be interrupted as it could
lead to a very weird state.
common: Report edeploy version used during build

When building roles and keeping logs for analysing a problem, it's
useful to get the git version that got used during the build.
common: Fixing /dev/shm problem

/dev/shm caused some troubles for the ubuntu target :
    mkdir: cannot create directory `/dev/shm': File exists

In fact, the shm was synced as it's a relative exclude.
common: compute the md5 sum of the archive
[ansible] Install subdirectory on the config files

The directory config have subdirectory now, allow ansible to install
them
init: specify we do IPv4 for now

This to ensure an interface with IPv6 address will be seen as
configured.
init: indent
doc: libfrontier-rpc-perl is a new debian dep

Perl Frontier::Client lib was introduced as a new dependency by
6b99356a4a2702ad34fd94d87bc8354b2748f706

On Debian, the package is called libfrontier-rpc-perl