* subdirs.am: This file is the exception: clean recursive targets

* subdirs.am: This file is the exception: clean recursive targets
are called by the clean targets, not the clean-am targets.
Otherwise we have a circular dependency: clean -> clean-am ->
clean-recursive -> clean.
* automake.in (handle_clean): Bind `-local' targets to `-am'
targets, not top targets.
Don't declare -recursive dependencies of the clean targets:
`subdirs.am' did it.  Less hard coded knowledge, transfered
into...
* clean.am: here.