Tweak Util module

Move UtilTests.py from the top level to the Util package directory,
for consistency with the other packages with unittests.

Renamed Util/types.py -> Util/sctypes.py.  types is the name of a stdlib
module and it's a bad idea to duplicate it, even though in this case it's
"legal" since the file was not at the top level.  (Moving UtilTests.py
actually made this a real problem)

Class Selector is no longer an OrderedDict, it just inherits from dict
as ordering is now preserved and we never used any extra features of
OrderedDict.

Fix API doc build - was missing a good bit of Util since it was split
into a package.

Moved the import-loop warning to the top of __init__.py so it will be
more visible.

Fiddly linting, doc-stringing, etc.  Super-fiddly: pylint flags foo, bar
and baz as prohibited variable/function/method names.  Actually changed
these in UtilTests.py.

SCons.Errors has been a source of import loops because it imports Util.
Now Util is split, directly import from the Util.sctypes submodule the
two things Errors needs - this may reduce the chance of import problems.

Signed-off-by: Mats Wichmann <mats@linux.com>

3 files changed, 39 insertions, 9 deletions

diff --git a/doc/sphinx/SCons.Util.rst b/doc/sphinx/SCons.Util.rst
new file mode 100644
index 0000000..553db7a
--- /dev/null
+++ b/doc/sphinx/SCons.Util.rst
@@ -0,0 +1,36 @@
+SCons.Util package
+==================
+
+Submodules
+----------
+
+.. automodule:: SCons.Util
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+.. automodule:: SCons.Util.envs
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+.. automodule:: SCons.Util.filelock
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+.. automodule:: SCons.Util.hashes
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+.. automodule:: SCons.Util.sctypes
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+.. automodule:: SCons.Util.stats
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
diff --git a/doc/sphinx/SCons.rst b/doc/sphinx/SCons.rst
index 45e20ee..85f5878 100644
--- a/doc/sphinx/SCons.rst
+++ b/doc/sphinx/SCons.rst
@@ -20,6 +20,7 @@ Subpackages
     SCons.Script
     SCons.Taskmaster
     SCons.Tool
+    SCons.Util
     SCons.Variables
     SCons.compat
 
@@ -140,14 +141,6 @@ SCons.Subst module
     :undoc-members:
     :show-inheritance:
 
-SCons.Util module
------------------
-
-.. automodule:: SCons.Util
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
 SCons.Warnings module
 ---------------------
 
diff --git a/doc/sphinx/index.rst b/doc/sphinx/index.rst
index f8d5f47..04bfdc2 100644
--- a/doc/sphinx/index.rst
+++ b/doc/sphinx/index.rst
@@ -17,7 +17,7 @@ SCons API Documentation
    The target audience is developers working on SCons itself:
    what is "Public API" is not clearly deliniated here.
    The interfaces available for use in SCons configuration scripts,
-   which have a consistency guarantee, are those documented in the 
+   which have a consistency guarantee, are those documented in the
    `SCons Reference Manual
    <https://scons.org/doc/production/HTML/scons-man.html>`_.
 
@@ -33,6 +33,7 @@ SCons API Documentation
    SCons.Script
    SCons.Taskmaster
    SCons.Tool
+   SCons.Util
    SCons.Variables