implemented callback server (+test cases), which can be informed by the vm after it has been started, if a script test/vmpool/puppet-base_etc_pptconnect.rb is copied to the vm and called in /etc/rc.local
added used rsa-key-pair to connect to sample base vm (TODO figure out, how to supply base vm online)
major refactoring of pool manager, including a callback server integration to ensure the puptest framework only tries to connect to vms via ssh after the have completely booted