#set( $command = ${project.commands.verifyTar})
Verifies the correct functionality of a project tar file by expanding, then
building and executing the unit tests inside. This can prevent the situation
where extreme care has been taken over the project source code, but correct
functionality of the subsequently released tar file is left to chance. Here are
the basic steps that are taken:
		
1. The tar file is extracted into the target directory, resulting in a failure
   if this goes wrong for some reason.
		
2. If there is no source directory then this results in a failure to avoid the
   situation where the caller mistakenly believes the tests to have been executed.
		
3. Maximum 'rwx' permissions are applied to the extracted files, since tighter
   restrictions can prevent compilation from working. One consequence is that
   the unmodified file permissions don't get tested.
		
4. The extracted project script is then executed using the compile, assemble
   and test commands. A failure of this execution results in command failure.
