0.4.2

Features:

• Symbol highlighting (@rwols)
• Polymer language server configuration (@rictic)
• Support RustEnhanced syntax

Major bug fixes:

• JSON-RPC & protocol parsing fixes (@vogelsgesang)
• Prevent completion failure if sortText was None.

Other noteworthy changes:

• Provide hook for 3rd party packages to listen to LSP messages:
  • See plugin_loaded in https://github.com/tomv564/LSP-rust/blob/master/plugin.py
• Some fixes for applying edits

As usual, thanks to all contributors and feature / bug reporters!