Corrects these bugs :  * Could not retrieve movies from the cameras (got the image having    the same base name instead).  Same behaviour for movie thumbnails.  * After correction of problem 1, got movie thumbnails that do    not fit the JPEG format.  * After correction of problem 1 & 2, part of some movie thumbnails had a    very bad quality! The phenomenon was aleatory.
Corrects these bugs :
 * Could not retrieve movies from the cameras (got the image having
   the same base name instead).  Same behaviour for movie thumbnails.
 * After correction of problem 1, got movie thumbnails that do
   not fit the JPEG format.
 * After correction of problem 1 & 2, part of some movie thumbnails had a
   very bad quality! The phenomenon was aleatory.

Following corrections were made :
 * Add call to sierra_change_folder in camera_file_get_generic,
   camera_file_get_info, camera_folder_delete_all, camera_file_delete.
   Remove sierra_folder_set from camera_start (then delete the routine
   since it is not used anymore).
 * Correct camera_file_get_generic to handle movie thumbnails
   correctly.
 * Correction in camera_file_get_generic regarding the properties
   (type and name) of the return file : it is always jpeg for thumbnails.
 * Move update_fs_for_folder and sierra_change_folder to library.c.
 * Remove formatting of the filesystem from camera_folder_delete_all : it
   is now performed by sierra_update_fs_for_folder.
 * Add a camera specific error code GP_ERROR_BAD_CONDITION which is raised
   when a picture cannot be captured (for instance if the lens protection was
   not removed, or the memory card is full).
 * Start documenting routines.

Tests :
 * Stuff was tested with an Epson 3000z (both USB and serial link).


git-svn-id: 40dd595c6684d839db675001a64203a1457e7319@2029 67ed7778-7388-44ab-90cf-0a291f65f57c

msmeissn/libgphoto2,thusoy/libgphoto2,jbreeden/libgphoto2,msmeissn/libgphoto2,gphoto/libgphoto2,msmeissn/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,msmeissn/libgphoto2,thusoy/libgphoto2,thusoy/libgphoto2,thusoy/libgphoto2,thusoy/libgphoto2,gphoto/libgphoto2,jbreeden/libgphoto2,jbreeden/libgphoto2,jbreeden/libgphoto2,jbreeden/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,msmeissn/libgphoto2