It appears that we can't start the FrameworkManager during static
initialization or the destruction of the FrameworkManager instance gets
instance gets confused.

Refs #7523

Refs #7263

The FileLoaderRegistry can now be asked to search its list of loaders
for the best that matches a given file. It passes along a *Descriptor
object to minimize the number of times the file is opened.

Refs #7263

The checks for the headers at the start of HDF4 & HDF5 files have been
put in a static isHDF member to encapsulate the details about
checking for a HDF file and make it reusable.
It will not retain an open file handle to the file so does not
inherit from the standard FileDescriptor.
Refs #7263

and also defines two types of loader, NonHDF and HDF.
Refs #7263

Refs #7263

It was previously not updating the version map when the algorithm was
removed and then subscribing the same thing again would throw an error.
Refs #7263

The stream is open for as long as the object is alive.
Refs #7263

FileDescriptor uses streams rather than c file handles. Refs #7263

Currently based on string names.