Add another target: chroot. Use this to make stuff on it.

Also the helper has been renamed to just chroot.sh.

--HG--
extra : convert_revision : 9d21ca6e9eb55a31a21cb800450376d60cf3af40

helper-templates/chroot.sh

@@ -80,6 +80,13 @@ install_chroot_pkg()
 	echo "==> Exiting from the chroot on $XBPS_MASTERDIR..."
 }
 
+enter_chroot()
+{
+	chroot $XBPS_MASTERDIR /bin/bash
+	umount_chroot_fs
+	echo "==> Exiting from the chroot on $XBPS_MASTERDIR..."
+}
+
 umount_chroot_fs()
 {
 	local fs=