* components/help/Makefile.am: Build converters. Stop installing
the now-unneeded .schemes file.

* components/websearch/ntl-web-search.c: Get rid of
gnome_button_can_default()

* libnautilus/nautilus-icons-view-icon-item.c: Get rid of missing
prototypes and associated warnings by including needed headers.

* src/ntl-types.h, src/ntl-uri-map.[ch], src/ntl-window.h,
src/ntl-window-msgs.c: Remove scheme mapping functionality (now
done in gnome-vfs). Use asynchronous version of get_file_info.