Moved NocaseDict and internal utility functions into their own submod…

…ules

Details:
- For general cleanup, moved class `NocaseDict` into its own submodule
  `_nocasedict.py`. Its unit test cases already had been in a separate
  sub module (`test_nocasedict.py`).
- In order to untangle existing circular import dependencies, as well as
  new ones that were created by the move of NocaseDict, moved the following
  utility functions into a new submodule `_utils.py`:
  - `_stacklevel_above_module()`
  - `_ensure_unicode()`
  - `_ensure_bytes()`
  - `_ensure_bool()`
  - `_hash_name()`
  - `_hash_item()`
  - `_hash_dict()`
- Adjusted any code that imports the moved symbols, to now import them from
  their new submodules. As part of that, several runtime-imports could
  be moved back to become module-level imports.
- Adjusted the documentatzion for the new module structure. This did not
  result in any changes to the generated documentation.

Signed-off-by: Andreas Maier <maiera@de.ibm.com>

docs/changes.rst

@@ -31,6 +31,10 @@ Released: not yet
 
 **Enhancements:**
 
+**Cleanup**
+
+* Moved class `NocaseDict` into its own module (Issue #848).
+
 **Known issues:**
 
 * See `list of open issues`_.

docs/client/objects.rst

@@ -6,6 +6,13 @@ CIM objects
 
 .. automodule:: pywbem.cim_obj
 
+.. _`NocaseDict`:
+
+NocaseDict
+^^^^^^^^^^
+
+.. automodule:: pywbem._nocasedict
+
 CIMInstanceName
 ^^^^^^^^^^^^^^^
 

makefile

@@ -131,6 +131,7 @@ doc_dependent_files := \
     $(package_name)/_subscription_manager.py \
     $(package_name)/_valuemapping.py \
     $(package_name)/_version.py \
+    $(package_name)/_nocasedict.py \
     $(package_name)/cim_constants.py \
     $(package_name)/cim_http.py \
     $(package_name)/cim_obj.py \

pywbem/__init__.py

@@ -33,9 +33,11 @@
 import sys
 import logging
 
+from ._utils import *  # noqa: F403,F401
 from .cim_types import *  # noqa: F403,F401
 from .cim_constants import *  # noqa: F403,F401
 from .cim_operations import *  # noqa: F403,F401
+from ._nocasedict import *  # noqa: F403,F401
 from .cim_obj import *  # noqa: F403,F401
 from .tupleparse import *  # noqa: F403,F401
 from .cim_http import *  # noqa: F403,F401