Eliminate remaining compiler warnings in MSVC++ 2008 32 bit with warning level 4

Dear abv,
Please, review the fixes in branch CR24129

+  // To eliminate compiler warning C4706:

Please avoid redundant comments in the code.

> if ((err = LoadShapes(ns1,ns2))) return err

These lines could be replaced by extra method to keep readability and resolve warning.

+#ifdef OCC2932

Please clean up code from this macros rather than adding new #ifdef.

+#define IP_III_DEB

This is uncommon way to define debug macros to disable debug code.

I've made the necessary fixes.
Please, review.

I have pushed my corrections to CR24129_1, please review

Patch is ready for testing.

Dear Commenter 2,

Branch CR24129_1 was compiled on Linux platform.
[revision removed]

There is compilation error:
http://jenkins-test-02.nnov.opencascade.com:8080/user/mnt/my-views/view/CR24129_1/job/mnt-CR24129_1-master_build_occt_linux/1/parsed_console/?
../../../../src/ViewerTest/ViewerTest_ViewerCommands.cxx:513: error: ‘theDisplayName’ was not declared in this scope

Please postpone testing this issue until branch CR23934 is tested: the fact is that the latter was based on CR24129 and still contains its commits. If CR23934 is tested without regressions, it should be integrated as two commits: one for CR24129, another for CR23934. I will do necessary rebasing when needed.

Dear Commenter 2,

Branch CR23934 ( #0023934 ) is TESTED.