major cleanup of lxc vm creation script

major cleanup of lxc vm creation script
new signature (one argument, the domainname, the rest as options, even if some are required, like e.g. the hostname for the ltest mode)
does not require to specifiy an ethernet interface, can figure it out
does not require an IP address, can figure it out
only use ‘ip’ and not ‘ifconfig’ or ‘route’ anymore
trashed sequels of lxc-tools (config file)
at this point only tested in ltest mode, lbuild is underway
note that this requires changes to the tests module as well since the signature has changed