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
Merge pull request #260 from david-christiansen/master

Support displaying embedded errors in docstrings