Release 0.9.0

[0.9.0]

New

• New builder pattern for creating nodes.
• New start_houdini_server function will launch Houdini application
  with engine server running in it. See live_session.rs example.
• Add many missing library functions.
• Find parameter with tags: Node::parameter_with_tag
• Interactive GUI app example that renders the COP network and displays as image.
• Assets can be loaded from memory
• Can now revert parameter values to default.
• Can now remove parameter expressions.
• New Parameter::save_parm_file to save the file from the parameter to disk.
• Can now delete geometry attributes.

Changed

• Simplified Session::create_node only take node name now. Use builder pattern for
  more options.
• connect_to_pipe now take an optional timeout parameter, and will try to connect multiple times
  until connected or timeout runs out.
• State enum renamed to SessionState
• Move all tests from modules to /tests/..
• Improved image extraction APIs.
• Add support for creating nodes for more asset types with less boilerplate code.
• Fixed setting of array geometry attributes.