LCGDM-1415: add default value 151 for lcgdm user (normally dpmmgr)
bump version
LCGDM-1415: run useradd manually in exec
qualify the exec shell commands
add a requirement to run the user creation after the group creation
revert the specification of the dpmmgr UID

mark it explicitly as undef in the params.pp
To specify it, admins should include

class{"lcgdm::base::config":
  uid => 151,
  gid => 151,
}

in their manifests.

The should NOT do it for already installed dpms,
ony for new installations
change the behaviour of adding dpmmgr uid and gid

use ensure_resource to instantiate the base and base subclasses.
add config params to set the dpmmgr uid and gid.
add convenience function staticuid to ns.pp and dpm.pp
also define the variables when staticuid is not wanted
soften the ensure_resource by if else
make the declaration of lcgdm::base explicit
simplify the specification of the dpm UID

if using the lcgdm::ns and lcgdm::dpm classes directly,
add:
class{"lcgdm::base":
  uid => 151
}

if using lcgdm, add the parameter:
class{"lcgdm":
  ...
  uid => 151,
}
also dbmanage can now be used here.

Using lcgdm::ns and ::dpm without declaring lcgdm::base
becomes an error
guard the lcgdm::base def
delete unused xrootd template
let the uid param also be specified by ns.pp
fix deps
LCGDM-1438: change default #FTHREADS to 60 (was 20)
fix warning about accessing variables in templates without '@'
fix for [LCGDM-1367] : Wrong NS configuration for LFC
fix for [LCGDM-1367] : Wrong NS configuration for LFC