Add foreach_slist() macro.
Make sorted_filetypes list public, and include None filetype first.
Rename filetypes_foreach_sorted() to filetypes_foreach_named() to
show it doesn't include the None filetype.



git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/branches/reorder-filetypes@3672 ea778897-0a13-0410-b9d1-a72fbfd435f5