Extend the BootstrapConfiguration in jclouds-chef to customize the chef-client run

Currently the BootstrapConfiguration object allows to customize the run list of a node and the environment where it should be registered. It should be extended to allow to configure other chef-client parameters, so it can be scheduled, configured as a daemon, etc.
All the information could be stored in a "chef-client" key in the bootstrap data bag so it can be reused by all the nodes in the same group.