Highlight files with no newline at end of file

Summary: Text "No newline at end of file" was sent to highlighter causing error with most languages.

Test Plan: Display diff containing file with no newline at end of file.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1903