remove unneeded thumbnail_requests list ptk-file-list.c
Apparently vfs_thumbnail_loader_request() is thread-safe after all. It
appears the thread race re g_slist_prepend was causing the issue in
g_slice_new0, so the thumbnail_requests addition has been removed.
remove use of main loop idle in async task and thumbnail loader; debug info
This commit is a partial work save, with debug output still enabled.
Remaining issues after this commit:
* dir object not always finalizing under extreme tests
* use of gtk_widget_queue_draw in on_dir_file_listed not thread-safe
Use of g_idle_add with multiple threads causing issues on status bar updates
during refresh and dir load, so use an event timer for the main window instead.
This handles the issue of content and selection change signals firing too
often when many files are selected.
