LibRaw 0.8.1 available for download

Changes are:

• Imported dcraw 8.97/1.427: new cameras: Canon A470, Canon G11 (without color data), Nikon D3000, Olympus E-P1, Panasonic DMC-FZ35/FZ38
• Fixes for Microsoft Visual C++ 6.0 compatibility
• C-API libraw_dcraw_make_mem_thumb() call finally exported in API