Improved console input reading within debug application
Fixed 701ecb94f2 since zero is a valid SANE handle
Print device information even if it could not be opened
Fixed invalid conditions with possible invalid memory access
Fixed small formatting issues
Added missing break statements
Improved experimental ADF support using the SANE scanning approach

This commit extends the experimental ADF support to detect the
availability of paper by trying to start a scan operation. If that
fails, the scan is cancelled and the driver returns that there
is no paper within the ADF tray.