More Digital File Format Management Tools

I added a some new entries to the Digital Preservation Tools and Services subsection for file format utilities.

One of the additions, ffident is a Java metadata extraction file format identification library, an is meant to serve as a component with other tools.  Another, FITS (File Information Tool Set), goes the other way and bundles several other tools to identify and validate formats.  The other addition is the NLNZ Metadata Extraction Tool, which extracts file format metadata and is useful for format identification.

Suggestions for  and comments on the list are welcomed!