20130905.3

1) add http/ftp/https support.
   for now only syntax:
   slackpkg {install/upgrade/reinstall} http://site/repo/package.txz

2) use wget forzately

3) fixed a bug that does not allow to install from a directory

4) allow to uninstall packages even if you specify the '.txz' in
   syntax:
   slackpkg remove package-1-noarch-1.txz