Fixed import_tab.t text

Multiple issues:

First, the imported file was UTF-8, not latin1 (it contains both latin2,
slovenian, and latin1 characters, so impossible to write in latin1).

Second, the PO object probably expects a decoded string, so do it accordingly.

Or, at least the test expects it so.
Set the input encoding on the command line or use legacy latin1
Add iclocales2gettext script to MANIFEST.
Fix noise from import tab script.