* retry failed downloads a few times before giving up and exiting
* detect and exit upon failed archive extraction
* more verbose and explanatory message for re-installing packages
Fixes#6426 and resolves a TODO.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37913 a95241bf-73f2-0310-859d-f6bbb57e9c96