[win32] Implement new Win32File

Reimplemented interface for VFS for local file access on win32.
* rewritten from scratch
* correctly handle all over/under sizes of variables
* automatically hide files in filesystem with name starting 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 system stat() (more accurate time values, set real number of hard links, better set _S_IEXEC attribute etc.)