win32: fixed window focus problem on account dialog and filter dialog.
fixed focus problem in win32.
prefs_filter_open(): correct focus when msginfo is specified.
moved two functions from prefs_filter.c to filter.c.
moved prefs_filter_read_config() to filter.c.
separated UI code from prefs.c.
added wrappers for C library function that take pathname arguments.
fixed Turkish locale problem.
made some buttons stock button.
made column of TreeView resize automatically.
reimplemented filter prefs dialog using GtkTreeView.
prefs_filter.c: use stock buttons.
replaced intl.h with glib/gi18n.h.
use GTK stock button for alertpanel.
use GTK stock button for dialog button set.
implemented the migration of configuration.
automatically take over older config files.
removed resize grip of the statusbar of main window.
Initial import of Sylpheed (GTK2 version).