wip: docs metrics start
metrics documentation changes, changed history endpoint to runs, gauge example, querying by run-id
make all implementations of getDataSet() throw DataSetInstantiationException
rename DataSetInstantiationException to DatasetInstantiationException (no more camelCase)
rename DataSetContext to DatasetContext (no more camelCase)
update to docs based on code review comments
rename DatasetContext.getDataSet() to getDataset(); keep old one as deprecated
small simplification
also rename DataSetInstantiator
remove legacy getDataSet() instead of deprecating it
Marked procedure related api as deprecated.
Wrap intialize and destroy methods of HttpSerivceHandler in txExecutor
Moving keys and values to constants
Missed one
Merge branch 'feature/get-ds-exceptions' into release/2.6.0
code review comments
Spark Integration: Collect system metrics from Spark
change based on review comments
Merge pull request #713 from caskdata/feature/cdap-761-deprecate-api

Marked procedure related api as deprecated.
Merge pull request #716 from caskdata/feature/spark-metrics

Spark Integration: Collect system metrics from Spark