v0.3.0 — Better symlink support

• Handling of symbolic links is changed: Now, if in_place is asked to operate on a symlink link.txt that points to realfile.txt, it will act as though it was asked to operate on realfile.txt instead, and the path link.txt will only be used when combining with backup_ext to construct a backup file path
• Drop support for Python 2.6 and 3.3