Add ConvertService to gateway

Added convert() convenience method for accessing the ConvertService.

Author: hinerm

src/main/java/org/scijava/AbstractGateway.java

@@ -37,6 +37,7 @@
 import org.scijava.app.StatusService;
 import org.scijava.command.CommandService;
 import org.scijava.console.ConsoleService;
+import org.scijava.convert.ConvertService;
 import org.scijava.display.DisplayService;
 import org.scijava.event.EventHistory;
 import org.scijava.event.EventService;
@@ -118,6 +119,10 @@ public ConsoleService console() {
 		return get(ConsoleService.class);
 	}
 
+	public ConvertService convert() {
+		return get(ConvertService.class);
+	}
+
 	@Override
 	public DisplayService display() {
 		return get(DisplayService.class);