Add recipe to built package contents

[jrray]

Since packages are not carrying all the same information as recipes anymore, we would like a way to capture the full recipe for every build. Because there is only one "version spec" per version, but builds can be built from different recipes, then to be able to have the correct recipe for any given build then it makes sense to copy the recipe into the package's metadata directory.

[rydrman]

From the meeting today:

• agreed that this file should be captured somewhere

• would this be considered sensitive, ever?

• if we add it into the source package, then it keeps it with items of a similar sensitivity level

• though we still only have one source package per version which may mean that some builds lose their full recipe if done using separate invocations

• seems good enough for now - at least in the service of debugging and digging into published data via spk info, etc

• instead, it seems better to just include the full recipe in the metadata directory of each build (like we do for options) so that tools like info can read that file back