API change request (RT-23413)

[Greg Brown]

This change would add a clearImports() method to FXMLLoader. See http://javafx-jira.kenai.com/browse/RT-23413.

Justification (from JIRA):

"If the FXMLLoader is used to load the same fxml-file mutliple times, it should be able to cache the collected information about classes and properties between the load() calls. This would massively improve the performance when using one fxml-file to describe an arbitrary number of objects."

Implementation:

FXMLLoader no longer clears the imports when load() is called; instead, any previous imports are preserved. Callers can explicitly clear the imports via a new method named clearImports(); however, in practice, this won't generally be necessary, since FXMLLoader instances are typically only used once and then disposed.