* The extract tool determines and reports all missing ports at once.
* The extract tool automatically prepares all missing ports if PREPARE_PORTS=1.
* The missing_ports tool prints a list of missing ports for given archives.
Fixes#3353
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
Ehmry -
Martin Stein
Roman Iten
Norman Feske