Use DNS for resolving {REPOSITORY,PROXY}_HOST
Merge pull request #54 from timotm/use-dns-for-jenkins

Use DNS for resolving {REPOSITORY,PROXY}_HOST
Change VMware network to use bridging.
Use bridging only if explicitly asked to do so.
Removed Vagrant version check (dropping support for v1).
Remove VMware specific bridging setup.
Removed references to vagrant_old.
Added variables for configuring Vagrant network type.
Use default networking if DIGABI_NETWORK_TYPE not specified.
Allow overriding Vagrantbox by provider.
Override box_url if using VMware Workstation.
Do not override (sed s//g) basebox in jenkins-build.