Added: projection version increments; writing projection version with
checkpoint tag; new short checkpoint tag format;
Added: projection epoch support + projection epoch support in emitted streams
Changed: emittedStream always checks ExpectedTag for equality; fixed
MultiStreamProjectionManager to always set exact ExpectedTag
Merge branch 'dev' into projections-reset
Added: tests on correct setting isJson in event readers
Added: projection epoch support when reading tagged stream
(DefaultCheckpointManager/MultiStreamMultiOutputCheckpointManager)
+ Tests for MultiStreamMultiOutputCheckpointManager
Added: test on starting a projections with a checkpoint in a past epoch
Added: resetting projections (no UI) + tests.  NOTE: resetting without changing
effective name.  Effective name change is to be added.
index on dev: 646dd9b Merge branch 'dev' of github.com:EventStore/EventStore into dev
WIP on dev: 646dd9b Merge branch 'dev' of github.com:EventStore/EventStore into dev
Merge commit 'ab351a5076d3652fe9ec1012e68fb9196ce2b16f' into projections-categories
Merge commit '909c10d54a81e6ebb68a6b39f72e0d90d38100a8' into projections-categories
Changed: Fixed metadata property naming - start system properties with $.
Added: Extra metadata support with CheckpointTag + writing $o (original stream)
with links emitted by event categorization projection.
Merge branch 'projections-categories' into projections-reset
Refactored: projection epoch/version replaced with ProjectionVersion structure
(not tested)
Changed: checkpoint tag serialization with full projection (id, epoch, version) stamp
Changed: view projection(s) layout
Added: displaying result stream name(s) on view/edit projection screens
Merge branch 'projections-ui' into projections-reset

Conflicts:
	src/EventStore/EventStore.Projections.Core.Tests/Services/core_projection/TestFixtureWithCoreProjection.cs
	src/EventStore/EventStore.Projections.Core.Tests/Services/core_projection/when_creating_a_projection.cs
	src/EventStore/EventStore.Projections.Core.Tests/Services/core_projection/when_starting_a_projection.cs
	src/EventStore/EventStore.Projections.Core/EventStore.Projections.Core.csproj
	src/EventStore/EventStore.Projections.Core/Services/Processing/CoreProjection.cs
	src/EventStore/EventStore.Projections.Core/Services/Processing/ProjectionCoreService.cs
	src/EventStore/EventStore.Projections.Core/Services/Processing/ProjectionNamesBuilder.cs
	src/EventStore/EventStore.Projections.Core/Services/Processing/QuerySourceProcessingStrategyBuilder.cs
Changed: Do not display results section for projections not producing any
persistent results