Hopefully fix syntax highlighting with wx 3.0.x

I'm pretty sure this is the reason it stopped working at least (the second parameter in StartStyling is *supposed* to be ignored in wx3.0, but apparently not)

src/TextEditor/Lexer.cpp

@@ -128,7 +128,13 @@ void Lexer::doStyling(TextEditorCtrl* editor, int start, int end)
 		editor
 	};
 
-	editor->StartStyling(start, 0);
+#if wxMAJOR_VERSION < 3 || (wxMAJOR_VERSION == 3 && wxMINOR_VERSION < 1) \
+	|| (wxMAJOR_VERSION == 3 && wxMINOR_VERSION == 1 && wxRELEASE_NUMBER == 0)
+	editor->StartStyling(start, 31);
+#else
+	editor->StartStyling(start);
+#endif
+
 	if (debug_lexer)
 		Log::debug(S_FMT("START STYLING FROM %d TO %d (LINE %d)", start, end, line + 1));