* Preserve international characters on import/export
Fixes#1352. Preserve non-ASCII characters in project names on
project creation and filenames on export.
Uses existing filename cleaner with the addition of a few
more characters from StackOverflow, plus "#" which messes
up the download URL. Also URIencode download URL.
Removes unused I18N-incompatible cleaning function from
Wikidata extension rather than fixing it.
* Use common name cleaner function
Also preview cleaned table name instead of raw name, so user can see it.
Also add a TODO for better preview of column names