[AgileWiki] rebuild now faster, uses less memory

[Bill la F. <bil...@su...>]

Transactions normally hold all the updates for the log file in memory 
until the transaction commits. And if we're trying to rebuild the entire 
database, that's a pretty large amount of data. And it isn't even used, 
as rebuild does not create a log file.

I've now changed TKS and Rebuild to prevent the log file data from being 
created. Now we don't run out of memory when rebuilding.

This is a critical change, for without it we can no longer rebuild the 
database at agilewiki.org. So there might just be an early release of 
alpha30.

Bill