Unit test requesting presence of sourced data in the absence of broadcasting.

Sourced data from non-broadcasting sources will be used to merge data without collisions.
NOTE: Sourced data could be provided by default, at a small additional cost.
Sourced data is always provided when broadcast == false, even if there are no known recipients.
Add HasAll and GetAll methods to packet, to retrieve all decorated instances of a type.
Using atomic typedef in AutoSelfUpdate/
Add AutoMerge class. This collects all data of a specified type from a context.
Verify that AutoMerge satisfies the VerifyNonBroadcastOutput test.
Revised unit test to verify that broadcast and data piped to gather is collected, but data piped to other sources is not.
Pipe & Broadcast declarations Ignore AutoPacket type, since it is always broadcast.

When resolving all consistent types to pipe for A -> B, an AutoPacket argument in B indicates that all types sent by A might be referenced. Likewise, and AutoPacket argument in A means that all types requested by B might be supplied.

This enables the deduction of pipes from an initial call A::AutoFilter(AutoFilter&) or to a final call B::AutoFilter(const AutoFilter&).
Fixes incorrect attribution of data source to target.
Simplified AutoMerge and revised AutoFilterTest.VerifyMergedOutputs.
Fixing is_autofilter_arg assessments.
Changing nomenclature in AutoMerge.
Implementation of AutoStile.

This class can be used to make the execution of a sibling (slave) context dependent on the exaction of the (master) context enclosing AutoStile.
AutoStile injects data from the master context and extracts data from the slave context, according to its template arguments.
Unit test demonstrating use of AutoStile.
Removing assumption of context from AutoPacketFactory pipe & broadcast declarations.
Adding comments to AutoCheckout explaining avoidance of std::shared_ptr<AutoPacket>.
Adding AutoMergeStile to facilitate extraction of data gathered by AutoMerge. Also added helper PipeToMerge method.
Adding unit test demonstrating use of AutoMergeStile.
Coercion of auto_out to be compatible with lambda captures that do not forward.
Fix multiple decorations from AutoStile. Output decoration is deferred to lambda call.