MSVC: Use STREQUAL to check for WindowsCE

In the Platform/Windows-MSVC module it is not necessary to use MATCHES
because we are comparing against an exact string.
WindowsCE: Refactor setting of "WINCE"

Move it to the Platform/Windows module since it is independent of the
compiler used.  While at it, remove redundant "WIN32" setting from
Platform/Windows-MSVC since Plaform/Windows already sets its.
WindowsCE: Drop unused Platform/WindowsCE-MSVC module

This module was created to mirror Platform/Windows-MSVC.cmake, but this
is not necessary because nothing includes "Platform/<os>-<id>.cmake"
directly.  The Platform/Windows-MSVC module is only a helper for the
Platform/Windows-MSVC-<lang> modules.
Merge topic 'windows-ce-cleanup' into next

7079f33d WindowsCE: Drop unused Platform/WindowsCE-MSVC module
05373f7e WindowsCE: Refactor setting of "WINCE"
1acde6b0 MSVC: Use STREQUAL to check for WindowsCE
cmGlobalVisualStudio10Generator: Fix typo KHLM => HKLM
Merge topic 'vs10-comment-typo' into next

99e14a38 cmGlobalVisualStudio10Generator: Fix typo KHLM => HKLM