bin/runUnitTest: code readibility

The only functional change is the following:
- before: sys.path begins with [*/product/*/tests] followed by [*/tests]
- after: sys.path begins with [prj1/product/*/tests, prj1/tests,
                               prj2/product/*/tests, prj2/tests,
                               ...]
This should have no impact.

stack/erp5.cfg

@@ -239,25 +239,24 @@ entry-points =
   runUnitTest=Products.ERP5Type.tests.runUnitTest:main
 scripts = runUnitTest
 initialization =
-  import os
-  import sys
+  import glob, imp, os, sys
   import Products
-  [Products.__path__.insert(0, p) for p in reversed(os.environ.get('INSERT_PRODUCTS_PATH', '').split(':')) if p]
+  Products.__path__[:0] = filter(None,
+    os.getenv('INSERT_PRODUCTS_PATH', '').split(os.pathsep))
   Products.__path__.extend(reversed('''${products:list}'''.split()))
-  import Zope2
-  os.environ['SOFTWARE_HOME'] = os.path.abspath(os.path.dirname(os.path.dirname(Zope2.__file__)))
+  os.environ['SOFTWARE_HOME'] = os.path.abspath(imp.find_module('Zope2')[1])
   os.environ['ZOPE_SCRIPTS'] = ''
   parts_directory = '''${buildout:parts-directory}'''
-  repository_id_list = list(reversed('''${erp5_repository_list:repository_id_list}'''.split()))
-  temp_bt5_path_list = ['/'.join([parts_directory, x, 'bt5']) for x in repository_id_list]
   bt5_path_list = []
-  [bt5_path_list.extend([bt5_path, '%s/*' % bt5_path]) for bt5_path in temp_bt5_path_list]
+  test_path_list = []
+  for r in reversed('''${erp5_repository_list:repository_id_list}'''.split()):
+    r = os.path.join(parts_directory, r)
+    bt5_path = os.path.join(r, 'bt5')
+    bt5_path_list += bt5_path, os.path.join(bt5_path, '*')
+    test_path_list += glob.glob(os.path.join(r, 'product', '*', 'tests'))
+    test_path_list.append(os.path.join(r, 'tests'))
   os.environ['erp5_tests_bt5_path'] = ','.join(bt5_path_list)
-  sys.path[0:0] = ['/'.join([parts_directory, x, 'tests']) for x in repository_id_list]
-  import glob
-  product_test_path_list = []
-  [product_test_path_list.extend(glob.glob('/'.join([parts_directory, x, 'product/*/tests']))) for x in repository_id_list]
-  sys.path[0:0] = product_test_path_list
+  sys.path[:0] = test_path_list
 
 [test_suite_runner]
 # XXX: Workaround for fact ERP5Type is not an distribution and does not