Updated Documentation for automos, mapmos, and handmos. In mapmos, updated...

Updated Documentation for automos, mapmos, and handmos. In mapmos, updated unit test for priority=band. In ProcessMosaic, updated the GetBandIndex() method to return the same number when you use the band number or band name. For example, if band 3 is the emission angle, GetBandIndex() should return 3 whether you enter 3 or emission angle. Modified BandPriorityWithNoTracking() so valid data is always placed on top of the mosaic regardless of the placement criteria (priority=band). The only way to place special or null pixels is to check those options in mapmos or automos. Fixes #1620. Fixes #1623. Fixes #1617. References #1550.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@5766 41f8697f-d340-4b68-9986-7bafba869bb8