Started fixing Unicode file I/O on Windows
All file I/O should now go via wchar on Windows
Needs to be tested, though
Compilation fixed for: chown, lchown, symlink, lstat, mkdir
Compilation fixed for: execve, execv, fstat
libcore_io_Posix now compiles with Unicode file I/O for Windows
mingw-extensions now compile
libavian.a now compiles and links, and demo applications using it link okay
Got rid of double conversion (jchar* -> char* [utf8] -> wchar_t*), using direct cast (jchar to wchar_t) instead, should be way faster
Merge pull request #6 from bigfatbrowncat/windows_unicode_file_io

Windows file I/O switched to widechar-based Unicode