Feature/msvc discovery

It's finished !! Now, it fully support MSVC from 9.0 to 14.0, and all theses standalone distributions:
- Microsoft Visual C++ Compiler for Python 2.7 (MSVC++9.0, x86, amd64)
- Microsoft Windows SDK 6.1 (MSVC++9.0, x86, x64, ia64)
- Microsoft Windows SDK 7.0 (MSVC++9.0, x86, x64, ia64)
- Microsoft Windows SDK 7.1 (MSVC++10.0, x86, x64, ia64)
- Microsoft Visual C++ Build Tools 2015 (MSVC++14.0, x86, x64, arm)

Next step:
- Code review.
- Test it with some MSVC versions/Architectures/Python versions combinations.

I have also some comments on the global implementation:
- I think `msvc9_find_vcvarsall` can now be deleted.
- Maybe rename the file, by example "msvc_support.py".
- Maybe Implementing it (And other distutils patchs) for not be only called by "setuptools", but also by "pkg_resources": This will automatically activate patchs for some externals packages like "Cython" transparently.

Merged in JGoutin/setuptools-1/JGoutin/first-thanks-for-the-review-this-is-very-1456944704555 (pull request #180)

feature/msvc-discovery

* Add support for MSVC11 and 12 (Only few changes with actual code needed for them).
* Python 2 compatibility for winreg.

* Rename many variable to use the same names as in MSVC .bat files. This really help to compare the Python script with original sources.
* Split compute_env to EnvironmentInfo class.
* Continue to add support for MSVC14.
* Some more little fixes.

I tested your reviewed version, and it work (Tested only on Windows x86, Python 3.4, Windows SDK 7.1 actually).

I did the following changes :

* Add many docstrings, and improve existing ones.
* Change some comments that was unclear.
* Move .NET Framework directory/version finders in "RegistryInfo", like others.
* Started to add support for the MSVC++14.0 standalone compiler. (Note that this is Work in progress). This also help me to find what fail in actual structure.
* Add "msvc9_" prefix to actual patch functions and unpatched dict for better readability.
* Add VCforPython27 alternative in _augment_exception for IA64 (Arch not supported by VCforPython27)
* Replace "lib_extra" and "sdk_extra" by more generic "ccpu_dir" and "tcpu_dir" functions (For better compatibility with MSVC++14)
* Changes some parts (like VSTools) for reduce line length, avoid repetitions and improve PEP8.
* Make "unique_everseen" and "lookup" private.


But, it is not finished, I need at least to do:

- Finish MSVC++14 support.
- Remove patch for "find_vcvarsall" for MSVC++9 ? (Now "query_vcvarsall" patch also support VC++ for Python 2.7)
- Make more tests with more compilers/platforms/Python combination.
- Check compatibility with MSVC++11 and 12.
- Rename the file in "msvc_support.py" ? (not MSVC9 only)
- Rename "RegistryInfo" ?
- Make compute_env a class ? for split subparts like you did it for "RegistryInfo" and "PlatformInfo"

Have lookup return None when it fails, moving the moving much of the try/except logic into single-line fallback expressions.

Make function private and don't use a different name for it, as it performs the same purpose. Also, it doesn't set anything.

Improve support for standalones MVC++ 9.0/10.0 compilers by setting directly the environment if Vcvarsall.bat is missing or fail.