ENH: Add InnerOpticToPlusImageReader.

Convert from the InnerOptic SyncRecord to an itk::Image.  According to the
Plus format, the Tracker transform is stored in the Image's
MetaDataDictionary, which is also written out to a file when size in the
MetaImage format.
Merge pull request #156 from thewtex/inneroptic-to-plus

ENH: Add InnerOpticToPlusImageReader.