Enhanced the query optimizer so that virtual tables are able to
+ make use of OR and IN operators in the WHERE clause.
+
Speed improvements in the btree and pager layers.
+
Added the SQLITE_HAVE_ISNAN compile-time option which will cause
+ the isnan() function from the standard math library to be used instead
+ of SQLite's own home-brew NaN checker.
+
Countless minor bug fixes, documentation improvements, new and
+ improved test cases, and code simplifications and cleanups.