Add NEWS file

Keep folks informed of updates.

Change-Id: I6edc17deb16839809b048b78705e31ac8bea904f

NEWS

+NEWS for Blubber
+================
+
+Blubber is a command line tool to produce Dockerfiles from higher-level
+specifications in YAML. Also included is Blubberoid, which provides a
+simple web interface.
+
+v0.8.0 (Wed, 24 Jul 2019)
+-------------------------
+
+### Backwards compatibility notes
+
+* `v4` is the only supported version. Blubber, being not yet to a 1.0.0
+  release, has changed the compatibility of the `version` field to only
+  support `v4`.
+
+* Unify `copies` and `artifacts` configuration
+
+    tl;dr: `copies` and `artifacts` have been merged to just `copies`
+
+    Refactored `copies` configuration to allow for greater control over
+    when and which both local build context files and variant artifacts
+    are copied into the target image.
+
+    The new configuration introduces a "local" keyword to signify when a
+    `copies` entry should apply to the files from the local build
+    context as opposed to files from another variant's image during a
+    multi-stage build.
+
+        variants:
+          build:
+            copies:
+             - from: local
+               source: ./src
+               destination: .
+
+    Note that with this change, the user must now explicitly define
+    whether _any_ files should be copied in from the local build
+    context. None will be copied in by default.
+
+    To help keep configurations succinct, especially considering this
+    new requirement, and to approximate the old `copies: variant`, a
+    shorthand format and sane defaults for `source` and `destination`
+    (depending whether `from` is "local" or a variant name) were
+    implemented.
+
+        variants:
+          build:
+            copies: [local]
+          development:
+            copies:
+             - from: build
+             - from: local
+               source: ./config.dev.yaml
+               destination: ./config.yaml
+
+    The shorthand:
+
+        copies: [ref, ...]
+        # is equivalent to
+        copies: [{ from: ref }, ...]
+
+    And the following defaults are used when no `source` and
+    `destination` are specified.
+
+        copies:
+         - from: local
+         # defaults to
+         - from: local
+           source: .
+           destination: .
+
+        copies:
+         - from: variant
+         # defaults to two entries
+         - from: variant
+           source: /srv/app # the lives.in dir
+           destination: /srv/app
+         - from: variant
+           source: /opt/local # the shared lib dir
+           destination: /opt/local
+
+
+### Updates and changes
+
+* Added support for use-system-flag directive. The `--target` flag is
+  broken in Debian/Ubuntu due to a distro-specific --user install default
+  in versions prior to 18.1.1 (including the Stretch version).
+
+    <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=830892>
+
+    This behavior can be switched off by specifying the --system flag in the
+    install command.
+
+* Updated the go-playground validator to support "startswith" and
+  "endswith" validators to be used to validate images used for production.
+  See the example in policy.example.yaml for how this would be used.