APR-UTIL build breakage

[Jim Jagielski]

Since this morning, apr-util (trunk) is refusing to build:
   Making all in apr-util
   make[3]: *** No rule to make target `.make.dirs', needed by  
`buckets/apr_brigade.lo'.  Stop.
   make[2]: *** [all-recursive] Error 1
   make[1]: *** [all-recursive] Error 1
   make: *** [all-recursive] Error 1

As a stopgap, I copied over the .make.dirs from apr to apr-util.