Add FileUtils.listContents(URL)

This function lists the contents of a given directory recursively.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Rename poorly named class
Fix a bug in file directory traversal code

There was confusion between URLs and URIs
Break out a LutFinder class

Utilized from within DefaultLutService.

This LutFInder class with search the file system under ImageJ.app
and an internal jar for .lut files.
Fix bug in menu position initialization
Remove obsolete code
Reorder method declarations for readability
Add my initials to a comment
Make lut menu tree specification more flexible

It was the case that you could only have one lut of a given short
name (such as "Super Lut") in the whole menu tree. Now you can have
colliding lut short names by placing them in different submenu
directories.
Lut discovery changes for improved Windows support
Merge branch 'improved-lut-discovery'

Conflicts:
	core/core/src/main/java/imagej/util/FileUtils.java