Added support for .hdr format, atm just being converted to ldr after the exposure is applied.
cleanup dds file
PNG skips 16bit altogether at the moment for textureArray issues.
Generating image previews of image assets was failing
DDS remove redundant check for stream status.
STB requires the file to be free before being written to, move check to make sure we can open the path into gBitmap and remove FileStream checks from everywhere else.
