Rename "connection_manager" type to "connection_processor" type

This was really confusing...
Export the implementation of the ws_connection_processor
Change visibility of members of ws_connection_processor
Add connection manager interface+stub
Add implementation of create_connection_cb() callback
Add deinit-functionality to connection manager
Add function for manual creation of connection to fd

This patch creates a function in the connection manager to create a
connection to a fd manually.

It rewrites the creation-callback to use this function, to prevent
code-duplication.
Rewrite ws_connection_loadconf() to use ws_connection_manager_open_connection()
Initialize the connection manager in main()
Merge pull request #550 from matthiasbeyer/add-connection_manager

Add connection manager