Allow for 2 table versions during building - one for reading existing and one for creating new

[GoogleCodeExporter]

Table builders should support two versions: 1) one for reading any existing 
data; 2) one for creating new data.

Can be worked around by creating new empty table and copying.

Original issue reported on code.google.com by stua...@google.com on 9 Dec 2011 at 7:55