xbps-src: multiple improvements to messages and phases.

- Prefix all messages with 'Package 'pkgname (version)': ..." to really
  understand what's going on. Add more messages in some stages...
- Do not run pre/post_{configure,build,install} or do_{build,install} stages
  if they were executed successfully in the past.

xbps-src/shutils/chroot.sh.in

@@ -272,7 +272,7 @@ xbps_chroot_handler()
 	else
 		[ "$norm_builddir" = "yes" ] && \
 			action="-C $action"
-		env in_chroot=yes LANG=C PATH=$path \
+		env in_chroot=yes LANG=C PATH=$path _ORIGINPKG="$pkg" \
 			${chroot_cmd} $XBPS_MASTERDIR sh -c \
 			"cd /xbps/srcpkgs/$pkg && xbps-src $action" || \
 			rv=$? && _umount && return $rv