Add simple performance tests for scanner functions
Use gtester and add test and report make targets

Use the GLib testing utilities gtester and gtester-report to log and
generate reports from tests. Create targets for tests and test
reporting, and add further targets for more granular selection of tests.
Use "make full-report" to run all GTest tests and generate an HTML
report of the results.
[l10n] Updated Italian translation.
Avoid NULL deref in Scan_Rename_File_Prefix_Path()

Check if the current path is non-empty before trying to use the name of
the currently-displayed file.

https://bugzilla.gnome.org/show_bug.cgi?id=727876
https://retrace.fedoraproject.org/faf/problems/1641130/
Move main window to EtApplicationWindow object
Pass the main window to actions as user data
Move log area to EtLogArea object
Move playlist window to EtPlaylistDialog object
Move load filenames dialog to EtLoadFilesDialog
Move file search dialog to EtSearchDialog object
Move preferences dialog to EtPreferencesDialog
Move CDDB dialog to EtCDDBDialog object
Move scan dialog to EtScanDialog object
Replace strncat() with g_string_append()
Move select and unselect actions to main window
Move file selection actions to EtApplicationWindow
Set a rough initial window size and pane positions
Move browser to EtBrowser object