Fixed tftpboot symlink check

As it is possible to use autofs to mount the medias we need to set
symlinks to the autofs root folder. Now the condition checks if the
symlink is set within the tftpboot root, if it is everything is fine, if
it points outside of the root the installation stops with an error
message.
Merge pull request #2063 from tboerger/feature/symlink-check

Fixed tftpboot symlink check
$MEDIA already expands with install
Merge pull request #2064 from dirkmueller/master

Switch to Cloud 5
Merge pull request #2066 from MaximilianMeister/master

$MEDIA already expands with install
Install crowbar-openstack before neutron

neutron installation fails because it depends on crowbar-openstack cookbook.
The error message is:

    Installing barclamp neutron from /opt/dell/barclamps/neutron
    ERROR: /opt/dell/barclamps/neutron knife cookbook upload -o . neutron -V -k /etc/chef/webui.pem -u chef-webui upload failed.  Aborting; examine /var/log/crowbar/barclamp_install/neutron.log for more info.

And neutron.log content is:

    Uploading neutron        [1.0.0]
    ERROR: Cookbook neutron depends on cookbook crowbar-openstack version >= 0.0.0,
    ERROR: which is not currently being uploaded and cannot be found on the server.

**This commit is forward-ported from 6c8cf21ff4cd54265ed7bdba1fb81b56c8679da2**
Relax SLES media check

* Fixed tftpboot symlink check
* Also accept the SUSE Cloud Deps media instead of SLES media

**This commit is back-ported from d782e7adf35224ae11019e020817114efd80892b, dd2d23f5b6986f12616890185820a1f3fcb2ac5c and 28313f08d65cd50be37312cb85d3ac58c176a9c2**
Merge pull request #2065 from tboerger/feature/copy-to-stoney

Copied over the development files to stoney release
Relax SLES media check

When using the DEPS iso, SLES11-SP3-Pool is not needed.
adding SLE12 based repositories
Merge pull request #2067 from toabctl/skip-repos-for-deps-usage

Relax SLES media check
list all suse installation dirs
update comments
SUSE-Cloud-5-SLE12-* -> SLE12-Cloud-5-Compute-*
do not copy&paste
check both main installation repositories
Merge pull request #2068 from jsuchome/sle12

adding SLE12 based repositories
do not check for metadata yet
Merge pull request #2069 from jsuchome/sle12

do not check for metadata yet
Make SLE12 media optional

We currently do not want to require SLES12 media for
install.