Adding rawPixelDataToBuffer() function for access to compressed data read from scanline input files.

Changes to add rawPixelDataToBuffer(...) function to the OpenEXR library. This allows you to read raw scan lines into an external buffer. It's similar to the existing function rawPixelData, but unlike this existing function it allows the user to control where the data will be stored instead of reading it into a local buffer. This means you can store multiple raw scan lines at once and enables the decompression of these scan lines to be done in parallel using an application's own threads.
Removing comments used to flag changes by the Foundry. No code changes.