Provides basic font-lock for the JAPE (Java Annotation Pattern Engine)
https://gate.ac.uk/sale/tao/splitch8.html#x12-2150008 language used with GATE
(General Architecture for Text Engineering) https://gate.ac.uk/ created by
the University of Sheffield.

Originally based on "An Emacs language mode creation tutorial" by
Scott Andrew Borton, http://two-wugs.net/emacs/mode-tutorial.html