2007-07-20 [colin] 2.10.0cvs51

2007-07-20 [colin]	2.10.0cvs51

	* src/folder.c
	* src/folder.h
	* src/folder_item_prefs.c
	* src/folder_item_prefs.h
	* src/folderview.c
	* src/imap.c
	* src/imap_gtk.c
	* src/imap_gtk.h
	* src/news.c
	* src/news_gtk.c
	* src/news_gtk.h
	* src/prefs_folder_item.c
		Implement age-based caching: allow to
		specify a threshold for the offline synchronisation
		feature, and whether old cached bodies should
		be removed
	* src/toolbar.c
	* src/toolbar.h
		Fix label/tooltips
	* src/plugins/dillo_viewer/dillo_viewer.c
		Check that Dillo's installed