Enable default parameter values in scripts

You can now write:

  @int(value = 5) sigma

And the sigma variable will have a default value of 5 the first time
the script is run.

Nicer would be:

  @int sigma = 5

But implementing that would be more involved, and so should probably
wait till script parameter parsing is truly fixed as described in #156.

Author: ctrueden

src/main/java/org/scijava/script/ScriptInfo.java

@@ -461,7 +461,7 @@ else if ("visibility".equalsIgnoreCase(key)) {
 			item.setVisibility(convertService.convert(value, ItemVisibility.class));
 		}
 		else if ("value".equalsIgnoreCase(key)) {
-			item.setWidgetStyle(value);
+			item.setDefaultValue(convertService.convert(value, item.getType()));
 		}
 		else {
 			throw new ScriptException("Invalid attribute name: " + key);