Support :printdef over IDESlave

This adds the option to see the internal definition of a symbol to
right-click menus, as well as a command. There's no keybinding by
default.
Update test runner for new language-java dependencies
Support :pprint with a command
Merge pull request #252 from david-christiansen/print-def

Support :printdef over IDESlave
Change default warning face to red wavy underline

In terminal Emacs, use the default warning face instead. Fixes #253.
Merge pull request #254 from david-christiansen/print-def

Change default warning face to red wavy underline
Support displaying embedded errors in docstrings

See https://github.com/idris-lang/Idris-dev/pull/1655