Add better tests for web.py; fix some bugs found with spidering.

- _spider in web.py was actually failing to spider deeper than a certain
  point.
- Fixed multiprocessing pools to not use daemons and to allow recursive
  spawning.
- Added detailed tests for spidering and for finding archive versions.
- left some xfail URL finding exercises for the reader.
- Fix noqa annotations for some @when decorators

var/spack/repos/builtin/packages/util-linux/package.py

@@ -31,7 +31,7 @@ class UtilLinux(AutotoolsPackage):
     homepage = "http://freecode.com/projects/util-linux"
     url      = "https://www.kernel.org/pub/linux/utils/util-linux/v2.29/util-linux-2.29.1.tar.gz"
     list_url = "https://www.kernel.org/pub/linux/utils/util-linux"
-    list_depth = 2
+    list_depth = 1
 
     version('2.29.1', 'c7d5c111ef6bc5df65659e0b523ac9d9')
     version('2.25',   'f6d7fc6952ec69c4dc62c8d7c59c1d57')