This commit complements issue #4004 with support for the depot/create
tool. If CCACHE=1 is specified at the command line, the build directory
for building a binary archive is configured with 'CCACHE := yes'.
This patch changes the depot layout such that each archive is
represented as a directory that contains the versions of the archive as
subdirectories.
Issue #2610
The depot tool did not consistently distinct libraries from regular
targets when handling binary archives. The binary archive of a regular
target is located at <user>/<bin>/<arch>/<name> whereas a library is
located at <user>/<bin>/<arch>/<api>/<name>.
Fixes#2438
