Revert "chop() on filename not necessary, handled in library"
Revert "chop() on filename not necessary, handled in library"

This reverts commit 145d1afce1ab6582cedc41e41a12be509f114c4b.

Note: this chopping is for keeping the UI nice (mainwindow titlebar),
not because the corpus reader expects filenames without an extension.
In the end, we may want to provide some 'canonicalName' function in
alpinocorpus readers.

evdmade01/dact,evdmade01/dact,evdmade01/dact,rug-compling/dact,rug-compling/dact