Rewrite the test table chunker to exercise every attribute type.
Add table chunker support to the client API.
Create some table chunker regression tests.
Add thread locking to the generic table artifact chunker.
Table chunker loads individual columns on-demand.
Merge branch 'master' into table-chunker-refactor
Cleanup chunker locking.  Closes #88.
Rewrite the table chunker to load requested rows on-demand.  Closes #89.