FileUtils: allow optional "natives-" prefix
FileUtils: allow optional "natives-" prefix

This is necessary to support jogamp artifacts, such as:

* gluegen-rt-2.3.0-natives-android-armv6.jar
* gluegen-rt-2.3.0-natives-linux-amd64.jar
* gluegen-rt-2.3.0-natives-macosx-universal.jar
* gluegen-rt-2.3.0-natives-windows-i586.jar

scijava/scijava-common