TurboJPEG: Properly handle gigapixel images

TurboJPEG: Properly handle gigapixel images

Prevent several integer overflow issues and subsequent segfaults that
occurred when attempting to compress or decompress gigapixel images with
the TurboJPEG API:

- Modify tjBufSize(), tjBufSizeYUV2(), and tjPlaneSizeYUV() to avoid
  integer overflow when computing the return values and to return an
  error if such an overflow is unavoidable.
- Modify tjunittest to validate the above.
- Modify tjCompress2(), tjEncodeYUVPlanes(), tjDecompress2(), and
  tjDecodeYUVPlanes() to avoid integer overflow when computing the row
  pointers in the 64-bit TurboJPEG C API.
- Modify TJBench (both C and Java versions) to avoid overflowing the
  size argument to malloc()/new and to fail gracefully if such an
  overflow is unavoidable.

In general, this allows gigapixel images to be accommodated by the
64-bit TurboJPEG C API when using automatic JPEG buffer (re)allocation.
Such images cannot currently be accommodated without automatic JPEG
buffer (re)allocation, due to the fact that tjAlloc() accepts a 32-bit
integer argument (oops.)  Such images cannot be accommodated in the
TurboJPEG Java API due to the fact that Java always uses a signed 32-bit
integer as an array index.

Fixes #361