v1.3.3: Improved handling of mode bits

Merge pull request #250 from anishathalye/improve-mode

Improve handling of mode bits

v1.3.2: Prevent MemMapFs.Chmod from changing all mode bits

Merge pull request #249 from JohnStarich/bugfix/memfs-chmod-perm-only

Prevent MemMapFs.Chmod from changing all mode bits

v1.3.1: Fix panic when not filling up zipfs's read buffer

Merge pull request #247 from JohnStarich/bugfix/zipfs-read-small-file

Fix panic when not filling up zipfs's read buffer

v1.3.0: zipfs, AIX, symlink and readlink support, etc.

Notable changes:

• Add AIX support
• Add zipfs, an archive/zip-based read-only filesystem
• Add an optional interface for Symlink and Readlink

Other enhancements:

• TempFile support for wildcards instead of only prefixes
• Implement sftpfs.OpenFile method
• Add support for os.O_EXCL in MemMapFs

Bugfixes:

• Fixed the mem.File implementation to respect the io.ReaderAt contract by storing the original offset before the Read and restoring the offset after the Read.
• Return closed error in mem.File.Write() after mem.File.Close() has been called
• Add missing error check in RegexpFs.Open()

v1.2.2: Fix UnionFile.Readdir return when c <= 0

Update Readdir to match behavior of stdlib os package.

Fixes #197

v1.2.1: Fix missing bounds checking in UnionFile.Readdir

It will now return io.EOF at the end of the directory view.

Fixes #194

v1.2.0: Return nil in CopyOnWriteFs.MkdirAll when directory exists

Fixes #191