Fix long-standing typos in comments.
Improved rendering of LogEst values corresponding to real values near 0.0
in the tool/logest.c utility program.
Fix a couple of out-of-date comments in where.c.
Update a couple of test cases to account for the fact that this branch prefers an index scan and partial sort over a full-table scan and full external sort.
Add text to the header comment of whereLoopAddBtree() describing how the costs of various b-tree loops are estimated.