xbps-src: fix fetch phase with depends, performance improvements.

- The fetch phase *must* run after installing pkg dependencies,
  otherwise it could fail if we need them for fetching.

- Performance improvements for xbps-src. Only source shutils files
  at the start, not every time we use a function.

xbps-src/shutils/tmpl_funcs.sh.in

@@ -66,7 +66,6 @@ info_tmpl()
 	done
 	echo "$long_desc"
 	echo
-	. $XBPS_SHUTILSDIR/builddep_funcs.sh
 	check_build_depends_pkg
 	if [ $? -eq 0 ]; then
 		echo "This package requires the following build-time dependencies:"
@@ -284,8 +283,6 @@ set_tmpl_common_vars()
 {
 	[ -z "$pkgname" ] && return 1
 
-	. ${XBPS_SHUTILSDIR}/install_files.sh
-
 	FILESDIR=$XBPS_SRCPKGDIR/$pkgname/files
 	PATCHESDIR=$XBPS_SRCPKGDIR/$pkgname/patches
 	DESTDIR=${XBPS_DESTDIR}/${pkgname}-${version}