Improve build templates by not having to set ${triggers} in some cases.

There's no need to update triggers in the following cases:
 * Packages installing stuff into /usr/share/applications.
 * Packages setting $gtk_iconcache_dirs.
 * Packages setting $font_dirs.
 * Packages setting ${sgml,xml}_entries.

--HG--
extra : convert_revision : 11c74b41f8cf474e9bf4dbb961b1aa9c6f6540bf

srcpkgs/font-isas-misc/template

@@ -14,7 +14,6 @@ Add_dependency full font-util
 
 noarch=yes
 font_dirs="/usr/share/fonts/X11/misc"
-triggers="x11-fonts"
 
 post_install()
 {