Add the ability to use an index even if the left-most columns of the index
are unconstrainted, provided that the left-most columns have few distinct
values.
Add test cases for skip-scan.  Enhance "do_test" so that if the expected result
is of the form "/*..*/" or "~/*..*/" it treats the expected result as a glob
pattern rather than as a regular expression.  Fix a bug in ANALYZE result
loading associated with WITHOUT ROWID tables.
Improve the way that skip-scan loops are constructued.  Add test cases.
Improved the scoring of skip-scan loops.
Add VDBE comments to the beginning and end of skip-scan loops.
Add the "PRAGMA vdbe_eqp" command, only available with SQLITE_DEBUG.  Simplify
some of the other debugging logic.
In the shell tool, if an "EXPLAIN" command is executed in ".explain on" mode, attempt to automatically indent the bodies of loops in the output VDBE program.
Import the "PRAGMA vdbe_eqp" enhancement and the enhanced EXPLAIN formatting
the shell from trunk.  Fix a bug in skip-scan and add a test case to prevent
a regression.
Merge the skip-scan enhancement into trunk.
Make sure the progress callback is invoked prior to an SQLITE_ROW return if
it is overdue to be called.
Simplification to the progress callback check. On branch removed.