Ignore non-port related messages in native compactor driver

The view native compactor driver process needs to handle only
Port related messages. It can ignore receiving any messages
such as pause message sent by unit test.

Change-Id: Iafd4f15219933f37a28d618db79ea95bbad5b5e9
MB-7629 Fix view compactor incremental progress stats

The native view compactor can now send intermediate
progress of how much kvs are written at every percentage
progress intervals.

Change-Id: I4c9ddbfee0b0531733552d54f2eb92a5fe44cf6b
Fix updater stats task to stay until disk write is complete

The the updater progress stats is populated from
the docloader when documents are loaded into MapQueue.
Even after all documents are loaded to MapQueue, it takes
additional amount of time to sort records and and build/update
ondisk indexes. Even though loading is complete, we need to make
sure that the progress stats task should not dissapear until
the whole updater processing is complete.

Change-Id: Idf3d3304d488a0bf3851db1b2b172ea6e796f1e0
Add support for stopping native index builder

Similar to the native compacter and native btree updater,
added ability to send a stop message to the index builder
and wait for native process to exit.

Change-Id: Ibda0ef728100266508407f6512f6f12dac2080d3
Remove sorting step for mapreduce initial index builder

Native btree index builder takes care of sorting before
the btree build. Hence sorting step is not required from
erlang side for mapreduce views.

Change-Id: Iafee54d0d65ca4c5cd90389d91e258792776989e
Change updater batch record tmpfile size from 30MB to 50MB

Updater performance have improved after rewrites in the btree
writer layer. Hence, updater should be able to batch more data
and process in less time.

Change-Id: I6da304d4228ee14f6a09226a16087b40fd2fd4af