Added cycling through file name part selections when renaming files

Implemented a feature that allows cycling through various name
and extension selections in the file-renaming editor by consecutively
hitting the rename shortcut (F2 by default).

For simple names like "notes.txt", it will cycle through "notes.txt",
"notes" and "txt". For more complex names like "archive.tar.xz", it will
cycle through "archive.tar.xz", "archive", "archive.tar", "xz" and "tar.xz".
The feature will help users to quickly select part of the name they need
to rename.

In addition, fixed the warning appeared when consecutively hitting
the rename shortcut:
warning default unknown@0 # edit: editing failed