Added FITS Format

Converted the loci.formats FitsReader to an ome.scifio FITSFormat and
associated components. The FitsReader has been marked deprecated.
Updated LegacyContext's Service list

The LegacyContext is now constructed with only the ome.scifio.service
Services, instead of dynamically finding all available services on the
classpath. This is to prevent unnecessary searching and loading of, say,
ImageJ2 services.
Added HasSource interface

Added a common interface providing the close() and close(boolean)
methods. This API was being repeated in Metadata, Parser, Reader and
Writer and is now standardized.

As part of this change, the reset() method in Metadata was removed and
is now called as part of close().
Corrected setAxis in ImageMetadata

The setAxisType method in ImageMetadata will now rename the existing
axis at that index, or reorder the axes if the provided axis is already
present.
Added createImageMetadata method

The Metadata API now has a createImageMetadata method which ensures the
specified number of ImageMetadata are freshly initialized.
Updated comments on CoreMetadataListWrapper

Fixed heading name. Added missing comments.
Corrected ICSFormat RGB logic

ICSFormat was not properly tracking RGB images, and was duplicating axis
type population.

This logic was consolidated and updated to account for RGB images.