Run DScanner on itself (#479)

* Enable DScanner checking on Travis
* Fix linter warnings
* Set opequals_tohash_check to disabled
* Set could_be_immutable to 'disabled'
* Split expression back into multiple lines
* Set style to disabled
* Fix Makefile target

makefile

@@ -51,6 +51,9 @@ test: githash
 	./bin/dscanner-unittest
 	rm -f bin/dscanner-unittest
 
+lint: dmdbuild
+	./bin/dscanner --config .dscanner.ini --styleCheck src
+
 clean:
 	rm -rf dsc
 	rm -rf bin