Improve the '--debug-targets' option and rename it to --debug-building.

Now everything is nicely indented.


[SVN r26470]

tools/build

@@ -1 +1 @@
-Subproject commit f5231eba0f325c8fb3b749a95196c266d29d65e8
+Subproject commit 61f59a5b0f891535d6e369d4aec4b089934beb5e