Add the SQLITE_REVERSE_UNORDERED_SELECTS compile-time option that causes the
"PRAGMA reverse_unordered_selects" setting to be on by default.
Make the sqlite3_table_column_metadata() interface available by default and
without requiring the SQLITE_ENABLE_COLUMN_METADATA compile-time option.
Other sqlite3_column_* interfaces that have a run-time penalty even if they
are unused still require the SQLITE_ENABLE_COLUMN_METADATA option at
compile-time.
Lower the default SQLITE_SORTER_PMASZ value back to 10, where it has been for
the past couple of releases.  Applications that need a larger value can set
one.
Add extra tests to e_walckpt.test.
Fix the sqlite3_table_column_metadata() routine so that it gives the correct
answer for the "rowid" column in a WITHOUT ROWID table.  Enhance it so that
it can be used to check for the existence of a table by setting the column
name parameter to NULL.  The routine is now included in the build by
default, even without the SQLITE_ENABLE_COLUMN_METADATA compile-time option.
Fix typos in the documentation for sqlite3_table_column_metadata().
No changes to code.
Revise mutex handling by the sqlite3_win32_reset_heap() function.
Add new test file e_walhook.test.
Fix a typo causing a test error in e_walhook.test.
Fix a typo in the documentation for sqlite3_threadsafe().
Fix a race condition to do with very large index keys in shared-cache mode.
Add the threadtest4.c test program.  Not yet working.
Fix a bug in the threadtest4.c program.  Remove the keyinfo cache as it provides
minimal performance improvements, and then only at SQL preparation time, not
at runtime, and it has problems with data races in shared-cache mode.  We might
later add the keyinfo cache back but only enable it when shared-cache mode
is off.
Merge the cell overflow page number cache thread race fix from trunk.
Make sure the Btree mutex is held when setting the locking mode and the
secure delete flag when attaching a shared-cache database.
Remove the KeyInfo cache (for now - perhaps we will add it back in later - or
maybe not since it provides negligible benefit but adds a lot of complexity
and thread-safety risk).  Add a mutex to ATTACH to deal with a data race.
Add new tests to the threadtest4.c program.  Fix a long-standing data race
in WAL mode for shared-cache.
Add extra tests to threadtest3.
Add extra tests to threadtest4.c.  Fix a benign data race accessing the
text encoding using ENC(db).
Further enhancements to threadtest3 stress tests.