Remote manager operations

This is a work in progress implementation to add support for the managers to spawn agents without accessing the libcloud interface, but using the director. The API for handling requests on the server's side contains now only the functions for creating and deleting a node (this is where the interface for the nested cloud will be integrated).

There are still many harcoded configuration settings (urls, paths). If you want to test, please grep for TODOs in the committed files.