fix escript archive symlinked across drives

real_path method used while prim loading archive files was not taking into account
the fact that windows directory symlinks can be across different drives
(eg. c:\tmp\test is a symlink to j:\tmp\test). when performing a path split the drive
precedes the symlink, but that has be rewritten also since it's different. This issue
never arises in Unix since obviously there are no drives.
Merge branch 'fix_bug_windows_directory_symlinks' of github.com:lrascao/otp into fix_bug_windows_directory_symlinks