Proto commits in sladeware/groningen

These 10 commits are when the Protocol Buffers files have changed:

Commit:3a2dc0e
Author:Matt T. Proud

Drop deprecated checkpoint file field. This is no longer used by the in-memory data stores nor the externally- hosted ones.

The documentation is generated from this commit.

Commit:55a39f8
Author:Oleksandr Sviridenko
Committer:Oleksandr Sviridenko

Output pipeline ID into the ExperimentArg proto that is built.

Commit:d22d9c1
Author:Oleksandr Sviridenko

Output pipeline ID into the ExperimentArg proto that is built.

Commit:2564f61
Author:Oleksandr Sviridenko

Now application can request specific pipeline ID. This allows application to have own pipeline ID format and generate an ID from the scratch.

Commit:a82c554
Author:Oleksandr Sviridenko

Add support of subjects with default settings in an experiment. The number of default subjects can be set for a cluster or a group of subjects. Fix broken CSV file download.

Commit:d92a15d
Author:Mikhail Bushkov

Added additional_exec_paths configuration parameter.

Commit:a0a47f6
Author:dave bayer

Extend PipelineSynchronizer interface to have methods to allow a caller to sync with the pipeline points and add a synchronizer that will block the pipeline only at the end of the iteration.

Commit:e9bb976
Author:Mikhail Bushkov

* Introduced HistoryDatastore interface and 1 implementation: MemoryHistoryDatastore. * Cleaned up ExperimentDb not to use caches - we don't need to cache anything there, as we're using HistoryDatastore. * Changed DisplayMediator to use HistoryDatastore to display historical data. NOTE: that it still maintains the list of all unique subjects (to display all-time best performers) which may leak memory. This will be fixed later.

Commit:8ee98f6
Author:Mikhail Bushkov

* Added PipelineIdGenerator that is sharding-aware, i.e. its' API hash shardForPipelineId() method that determines the corresponding shard for every PipelineId. * Introdcued PipelineState - class that encapsulated all the information about current pipeline state. PipelineState can serialize/deserialize itself. It uses corresponding protobufs to do that. * Refactored ExperimentDb to not depend on any storage layer. Made ExperimentDb a part of PipelineState. * Implemented MemoryDataStore. * Implemented PipelineRestorer, which restores pipelines from their saved states on Groningen server startup.

Commit:0f4d921
Author:Matt T. Proud

Initial import of Groningen into version control.