apr: various improvements

This commit:
 * Adds licensing informations
 * Ensures the apr-1-config script gets fixed appropriately
 * Remove the usr/build-1/ directory from the target, since it is only
   used during the compilation of packages that rely on APR.
 * Fix up a few paths in usr/build-1/ so that the compilation of
   apr-util works properly on top of this apr package.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>