v0.7.0

Note: this release changes how symbolic links are handled. See below.

• TMSU now compiles for Mac O/S. (Thanks to https://github.com/pguth.)
• The VFS no longer lists files alongside the tag directories under tags.
  Instead there are results directories at each level, within which you can
  find the set of symbolic links to the tagged files.
• Symbolic links are now followed by default. This means that if you tag a
  symbolic link, the target file is tagged instead. To instruct TMSU to not
  follow symbolic links (previous behaviour) use the new --no-dereference
  option on the relevant subcommands.
• Added new setting symlinkFingerprintAlgorithm to allow the fingerprint
  algorithm for symbolic links to be configured separately to regular files.
• By default duplicate files will now be reported when tagging. A new setting
  reportDuplicates can be used to turn this off.
• Slashes are now permitted within tags and values, useful for recording URLs.
  In the virtual filesystem, similar looking Unicode characters are used in
  their place.
• Added --where option to tag subcommand to allow tags to be applied to
  the set of files matching a query.
• The VFS tags directory will now relist tags that have values so that
  multiple values can be specified, e.g. tags/color/=red/color/=blue.
• It is now possible to list tags that use a particular value with the new
  --value option on the 'tags' subcommand.
• Made it possible to upgrade the database schema between releases.
• Added --count option to untagged.
• Bug fixes.