Mega-commit with improvements and changes done in the past days.

- Introduce package states: unpacked, broken, installed, etc.
  Not yet finished, only unpacked and installed are used for now.

- Move package metadata files in binary packages directly to
  the top directory, this speeds up some ops and makes easier to
  continue working in future changes.

- xbps-bin: -C flag to check the hash of package files has been
  superseded by the 'check' target, which verifies the integrity
  of an installed package.

- Use the 'essential' object when upgrading packages, overwritting
  current files. This is needed for critical packages like sh, libc
  and others.

- Miscellaneous tweaks and improvements thorough the code.

--HG--
extra : convert_revision : 2073fcc123efc24b3e9327b5e22aa91752f20df6

shutils/metadata_scripts.sh

@@ -26,7 +26,6 @@
 xbps_write_metadata_scripts_pkg()
 {
 	local action="$1"
-	local metadir="${DESTDIR}/var/db/xbps/metadata/$pkgname"
 	local tmpf=$(mktemp -t xbps-install.XXXXXXXXXX) || exit 1
 	local fpattern="s|${DESTDIR}||g;s|^\./$||g;/^$/d"
 	local targets found info_files
@@ -217,7 +216,7 @@ _EOF
 			rm -f $tmpf
 			return 0
 		fi
-		mv $tmpf ${metadir}/REMOVE && chmod 755 ${metadir}/REMOVE
+		mv $tmpf ${DESTDIR}/REMOVE && chmod 755 ${DESTDIR}/REMOVE
 		;;
 	esac
 }