Added parsing of TileWidth and TileLength. Changed calls to readLong() to
readInt() as DATA_TYPE.Long is 4 bytes in the TIFF standard. Updated some
exceptions and their messages.
Added parsing of TileOffsets. Added check for 'number of elements' in a
directory entry (tag) to be less than what an integer can hold and changed
code to handle the number of elements as an int. Removed DATA_TYPE.getValue()
method as it is no longer needed.
Updated to JUnit version 4. Added test for Big TIFF file BigTIFFLong8Tiles.tif.
Path to this file is currently a local path; should change this in the
future to access on a share.
Added parsing of TileByteCounts with test.