Replace use of WIN32 CPP macro with _MSC_VER

[KineticTheory]

Background

• This is generally a more standardized syntax. Also, WIN32 might be defined for non-MSVC environments on Windows platforms like MinGW or MSYS.

Purpose of Pull Request

• fixes #500

Description of changes

• WIN32 is the correct variable to check within CMake files.
• Fix copyright blocks based on pre-commit-hook.

Status

• Reference:
  • Pre-Merge Code Review
  • CDash Status
• Checks
  • [x] Travis/Appveyor CI checks pass
  • [x] Code coverage does not decrease
  • [x] Valgrind test passes
  • [x] Toss3 checks pass
  • [x] Trinitite checks pass
  • [ ] Code reviewed/approved, sufficient DbC checks, testing, documentation

[codecov[bot]]

Codecov Report

Merging #1124 (0ef7b3a) into develop (39f9f38) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           develop   #1124   +/-   ##
=======================================
  Coverage     89.0%   89.0%           
=======================================
  Files          374     374           
  Lines        19261   19261           
=======================================
  Hits         17157   17157           
  Misses        2104    2104