Support additional file extensions in COMPILE_MATCHER.
Tests for additional file extensions in COMPILE_MATCHER.
Merge pull request #59 from neonichu/fixes

Support additional file extensions in COMPILE_MATCHER.
Basically working, doesn't contain absolute paths for file and directory.
Remove whitespace in front of compiler commands.
Added feature tests for the JSON compilation database reporter.
Merge branch 'json-compilation-database' of github.com:neonichu/xcpretty into json-compilation-database
Revert accidental duplication.