gluon-config-mode-core: move gluon-web base path to /lib/gluon/config-mode

- CGI script and index.html are moved from gluon-web to
  gluon-config-mode-core, the script is renamed to 'config'
- gluon-web and gluon-web-model base views and i18n files are symlinked
  into the new path
- gluon-web-theme is renamed to gluon-config-mode-theme and installs
  directly into the new path
- all gluon-web-* models, controllers and views are moved into the new
  path

package/gluon-web-mesh-vpn-fastd/luasrc/lib/gluon/web/model/admin/mesh_vpn_fastd.lua → package/gluon-web-mesh-vpn-fastd/luasrc/lib/gluon/config-mode/model/admin/mesh_vpn_fastd.lua

@@ -7,7 +7,7 @@ local s = f:section(Section)
 
 local mode = s:option(Value, 'mode')
 mode.package = "gluon-web-mesh-vpn-fastd"
-mode.template = "model/mesh-vpn-fastd"
+mode.template = "mesh-vpn-fastd"
 
 local methods = uci:get('fastd', 'mesh_vpn', 'method')
 if util.contains(methods, 'null') then