Windows: Added "--icon" option for applications.
Windows: Added --mingw option to force ignoring MSVC installation.

* Also output the compiler ultimately used to compile, which will
  be useful to debug MSVC selection process.

* Removed some scons flags from call of scons unless they are true
  so as to remove clutter from it.
Windows: Use batch mode for compiling with MSVC, should be faster.
Windows: Allow MSVC already in PATH to be used by scons.
Removed no longer relevant script.

Comparing to Cython has become useless.
Added test to cover order of deletion during iteration.
Cleanup, remove temporary blocks as scope

* The temporary blocks provided implicit scopes to temporary holder
  variables, make these explicit.

* Touches a lot of re-formulations, sometimes requiring adding a
  try/finally to cover.

* Work in progress, Python3 classes still have issues.
PyLint cleanups

* Avoid "locals" and "globals" as arguments as they collide with built-ins

* Added comments.
Remember user provided for constant references, we will need it later.
Changelog updates
Cleanup the scons file

* Make arguments that need no default have none.

* Don't use os/arch modes, the new target_arch can be used for these
  just fine.

* Enhanced documentation.
Developer Manual: Added design description for Scons parts
User Manual: Added contributor entry.
Developer Manual: Added references idea.
Minor cleanup, use normalized path for sys.path om checkouts
Cleanup, use "result_name" as Scons interface.
Fix, virtualenv needs enhanced stdlib path detections.
Added reasons for recursion or non-recursion decision.
Added another benchmark to look at.

Nuitka currently achieves practically no speedup on this one.
Cleanup, make uses "asObject" into "asObject0" or "asObject1" for better polymorphism.