Merge xbps-src code to make it usable in a standalone mode.

The new xbps-src configuration file is `etc/conf` where you can
add your local overrides from defaults set via `etc/defaults.conf`.

To use this xbps-src, run these steps:

	$ make
	$ sudo make setup (to make chroot helper setgid)
	$ ./xbps-src ...

common/xbps-src/libexec/xbps-src-dofetch.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+#
+# Passed arguments:
+# 	$1 - pkgname [REQUIRED]
+#	$2 - cross target [OPTIONAL]
+
+if [ $# -lt 1 -o $# -gt 2 ]; then
+	echo "$(basename $0): invalid number of arguments: pkgname [cross-target]"
+	exit 1
+fi
+
+PKGNAME="$1"
+XBPS_CROSS_BUILD="$2"
+
+. $XBPS_SHUTILSDIR/common.sh
+
+for f in $XBPS_COMMONDIR/helpers/*.sh; do
+	source_file "$f"
+done
+
+setup_pkg "$PKGNAME" $XBPS_CROSS_BUILD
+
+for f in $XBPS_COMMONDIR/environment/fetch/*.sh; do
+	source_file "$f"
+done
+
+XBPS_FETCH_DONE="$wrksrc/.xbps_fetch_done"
+
+if [ -f "$XBPS_FETCH_DONE" ]; then
+	exit 0
+fi
+
+# Run pre-fetch hooks.
+run_pkg_hooks pre-fetch
+
+# If template defines pre_fetch(), use it.
+if declare -f pre_fetch >/dev/null; then
+	run_func pre_fetch
+fi
+
+# If template defines do_fetch(), use it rather than the hooks.
+if declare -f do_fetch >/dev/null; then
+	cd ${XBPS_BUILDDIR}
+	[ -n "$build_wrksrc" ] && mkdir -p "$wrksrc"
+	run_func do_fetch
+	touch -f $XBPS_FETCH_DONE
+else
+	# Run do-fetch hooks.
+	run_pkg_hooks "do-fetch"
+fi
+
+# if templates defines post_fetch(), use it.
+if declare -f post_fetch >/dev/null; then
+	run_func post_fetch
+fi
+
+# Run post-fetch hooks.
+run_pkg_hooks post-fetch
+
+exit 0