init: factor paths out of spack/__init__.py and into spack.paths module

var/spack/repos/builtin.mock/packages/url-list-test/package.py

@@ -25,14 +25,14 @@
 from spack import *
 
 import os
-import spack
+import spack.paths
 
 
 class UrlListTest(Package):
     """Mock package with url_list."""
     homepage = "http://www.url-list-example.com"
 
-    web_data_path = os.path.join(spack.test_path, 'data', 'web')
+    web_data_path = os.path.join(spack.paths.test_path, 'data', 'web')
     url = 'file://' + web_data_path + '/foo-0.0.0.tar.gz'
     list_url = 'file://' + web_data_path + '/index.html'
     list_depth = 3

var/spack/repos/builtin/packages/cbtf-krell/package.py

@@ -41,7 +41,6 @@
 ##########################################################################
 
 from spack import *
-import spack
 import spack.store
 
 

var/spack/repos/builtin/packages/gobject-introspection/package.py

@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 from spack import *
-from spack import spack_root
+from spack.paths import spack_root
 
 
 class GobjectIntrospection(Package):

var/spack/repos/builtin/packages/openspeedshop/package.py

@@ -42,7 +42,6 @@
 
 from spack import *
 
-import spack
 import spack.store
 
 import os

var/spack/repos/builtin/packages/perl/package.py

@@ -30,12 +30,14 @@
 # Author: Justin Too <justin@doubleotoo.com>
 # Date: September 6, 2015
 #
-from spack import *
 import os
 from contextlib import contextmanager
-import spack
+
 from llnl.util.lang import match_predicate
 
+import spack.store
+from spack import *
+
 
 class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
     """Perl 5 is a highly capable, feature-rich programming language with over

var/spack/repos/builtin/packages/python/package.py

@@ -32,11 +32,11 @@
 from llnl.util.lang import match_predicate
 from llnl.util.filesystem import force_remove
 
-import spack
-from spack import *
+import spack.store
+import spack.util.spack_json as sjson
 from spack.util.environment import is_system_path
 from spack.util.prefix import Prefix
-import spack.util.spack_json as sjson
+from spack import *
 
 
 class Python(AutotoolsPackage):