scandoc: Move from pdfjam to pdfmerge That is much smaller, and avoids installation of TeXlive.
scandoc: Use pdfjam directly pdfjoin wrapper got removed in pdfjam 3.02
scandoc: Drop hardcoded USB bus/device address
build-devtoolbox: Unbreak syntax after dfe85b640
scandoc: Specify device and format
scandoc: remove temporary dir again
add scandoc