* olympus-desc.c, sierra-desc.h, sierra.c, sierra.h: Add changes
to support the 0x6 get register strings, the extended protocol.
This gives roughly twice the download speed. This is not
supported for the default cases. Thanks to Selmeczi David
<david@esr.elte.hu> for discovering and coding up the original
patch for this support. Also includes a minor change in
library.c for the message when a recursive call is detected.
git-svn-id: https://svn.code.sf.net/p/gphoto/code/trunk/libgphoto2@5521 67ed7778-7388-44ab-90cf-0a291f65f57c
8773afa472