make: be more robust against erasion of build dir
make: be more robust against erasion of build dir

Put the stamp file in the build dir.
Also, don't generate documentation.

Signed-off-by: Peter Soetens <4b8373d016f277527198385ba72fda0feb5da015@thesourceworks.com>

phamelin/orocos-log4cpp,phamelin/orocos-log4cpp,phamelin/orocos-log4cpp,orocos-toolchain/log4cpp,phamelin/orocos-log4cpp,orocos-toolchain/log4cpp