RIOT-OS/RIOT — pull request #1725 by LudwigOrtmann (2014-09-27 09:34:16+00:00)
Title: make: only depend on directories that don't exist

The timestamp of directories is updated when a file inside a directory
is changed.
Therefore, make decides a target needs to be rebuilt, whenever that
target depends on its parent directory, because the directory is
always newer than the file inside.