Update the file to reflect current implementation, as the tests
  were left w/o run for very long, some messages outputs were changed
  overtime.

  This may cause an import chicken-egg problem, so this also reduce
  the amount of imports to be done.

This reverts commit 18402f9f.

This reverts commit 3e54ec0c.

Use slapos.extension.strip instead.

This reverts commit f26567c4.

  And it is also backward compatible with buildout<2 and with current tests

It looks even better to change the default value on Download.__init__()

And something should also be done not to cache something local.

This reverts commit 3fddde03.