Allow selective auto-completion

[josephwright]

trafficstars

Currently the auto-completion list is all-or-nothing: there are multiple .txt files providing the data but they are all 'on'. It would be good if there were an interface to turn them on and off: would for example allow different 'modes of operation'.

[astoff]

I wrote a lua script that might help, see here. It calculates context-aware completions and documentation, and is meant to be extensible.