Wip for abort/rehab deadlock fixes.
Wip for abort/rehab deadlock fixes.

This is a different take on the deadlock problem in init. We add an
extra state 'post_init' whose purpose is to move the work of
initialization out of the init phase, and thus the
pushy_node_state_sup process.

chef/opscode-pushy-server,MSch/opscode-pushy-server,chef/opscode-pushy-server,MSch/opscode-pushy-server,chef/opscode-pushy-server