Fixes #18

See http://coq.inria.fr/distrib/V8.4pl3/CHANGES for relevant
protocol changes and
https://github.com/tauli/CoqIDE/commit/2e5578c8078c7aa60aee491d037cc6eed1ab3a8c
for sample fix in CoqIDE project.

Tested a bit on v8.4pl3 but not backtested on older versions.  Seems to work but I haven't done anything too complicated with it (still learning coq).