Fix build script under osx: import of "modules tests defaults" folders

Under osx cp's flag "-p" doesn't mean "--preserve". The best way is to
use rsync -R
Modifications to make content loadable under osx

Tb was unable to load ensemble's overlays inside the jar: avoid using
it; additionally, it seems that files are expected to live in a chrome/
subdirectory
small fix for mozIStorageConnection
Update supported version

Note that tb 17 under osx was throwing an import problem for
resource://gre/modules/Promise.jsm, so i suppose tb24 is the first safe
version here
added missing function for "Insert House" debug