IFile and CFile: add doxy for Stat() functions
[win32] WIN32Util::ConvertPathToWin32Form: add overload to use CURL& as parameter
[win32] WIN32Util: add fileTimeToTimeT() helpers
[win32][vfs] Implement new CWin32File class for local files on win32 platforms
* rewritten from scratch
* added a lot of validity checks and results checks
* correctly handle all over/under sizes of variables
* automatically hide files in filesystem with name staring from dot
* fixed bug - Write didn't update i/o pointer
* always return real current file size instead of cached value
* reimplemented Stat() better than common runtima stat() (more accurate time values, set real number of hard links, better set _S_IEXEC attribute etc.)
[win32][vfs] FileFactory: switch to new CWin32File class; remove HDFile from win32 project
Merge pull request #4984 from Karlson2k/win32file_01

[win32] Implement new Win32File