IMAGING-310 JpegImageParser.getImageInfo() Refactor colorType logic to first look at numberOfComponents

[jephillips34]

fix for IMAGING-310 JpegImageParser: Grayscale JPEG file with app14Segment returns ColorType.UNKNOWN

[kinow]

Thanks for the pull request and sorry for taking so long to review it @jephillips34 . Will try to get on it in the next days :+1:

[coveralls]

Coverage remained the same at 76.839% when pulling fcfafb6efebb52d5f4566344970ba551350b5c69 on jephillips34:IMAGING-310-JpegImageParser-colorType into b6b4e9c739ffc22fa0cdad3d54dd203682a47960 on apache:master.

[kinow]

Rebased onto master and squashed commits. Let's start reviewing it :)

[garydgregory]

Closing: No reply.