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/configure_funcs.sh

@@ -66,7 +66,6 @@ configure_src_phase()
 
 	# Apply patches if requested by template file
 	if [ ! -f $XBPS_APPLYPATCHES_DONE ]; then
-		. $XBPS_SHUTILSDIR/patch_funcs.sh
 		apply_tmpl_patches
 	fi