Add default canConvert(Class, Class) impl

We have enough information at the abstract layer to implement this
method. Doing so should allow us to reduce boilerplate method
implementations downstream.

Author: hinerm

src/main/java/org/scijava/convert/AbstractConverter.java

@@ -35,6 +35,7 @@
 import java.util.Collection;
 
 import org.scijava.plugin.AbstractHandlerPlugin;
+import org.scijava.util.ConversionUtils;
 import org.scijava.util.GenericUtils;
 
 /**
@@ -91,6 +92,12 @@ public boolean canConvert(final Object src, final Class<?> dest) {
 		return canConvert(srcClass, dest);
 	}
 
+	@Override
+	public boolean canConvert(final Class<?> src, final Class<?> dest) {
+		return ConversionUtils.canCast(src, getInputType()) &&
+			ConversionUtils.canCast(dest, getOutputType());
+	}
+
 	@Override
 	public Object convert(final Object src, final Type dest) {
 		final Class<?> destClass = GenericUtils.getClass(dest);