Give vhost related commands option to read template from file

We dynamically create vhosts via zs-client in an ant task. Passing the vhost template escaped as a commandline argument was just not possible. 

I built in a check that if the `--template` parameter resolves to a file path, then the content of the file i read in php. Usage:  `zs-client ... --template=/path/to/vhost.config`

This change should be BC. 

Do I have to re-generate the phar and add it to this pull request?