Refactoring: ::CreateFile
Code style.
Sysutils.cpp: Cleanup.
Refactoring: Use INVALID_HANDLE_VALUE instead of NULL; Use INVALID_FILE_ATTRIBUTES instead of 0.
Refactoring: ::FindFirstFileW.
Refactoring: ::FindFirstFile.
Refactoring: ::CloseHandle.
Refactoring: Use INVALID_FILE_ATTRIBUTES instead of 0.
Refactoring: ::FileExists.
Refactoring: Rename vars; ::CreateFile; ::GetFileAttributes
Refactoring: Use INVALID_FILE_ATTRIBUTES instead of 0.
Refactoring: Remove parenthesis.
Refactoring: Rename vars; ::FindNextFile; ::EnterCriticalSection; ::LeaveCriticalSection
FarPlugin.cpp: Minor code style improvement.
Refactoring: base: Replace NULL --> nullptr
Refactoring: core: Replace NULL --> nullptr
Refactoring: NetBox: Replace NULL --> nullptr
Refactoring: windows: Replace NULL --> nullptr
Refactoring: Rename parameters.
README.RU.md: Fix typo.