Interchange two conditions in an "if" statment in sqlite3PagerAcquire() for
very slight (0.06%) overall performance increase.
Avoid unnecessary calls to sqlite3VarintLen() from the OP_MakeRecord opcode.
Another simplification to the OP_MakeRecord opcode, making it slightly
faster and very slightly smaller.
Use putVarint32() instead of putVarint() for a quantity that can never
exceed 2GiB - 1.
Avoid unnecessary no-op calls from getAndInitPage() to btreeInitPage() 
in the btree.c logic.
Use memmove() rather than a home-made copy loop in dropCell() of btree.c,
for a size reduction and performance improvement.
Use memmove() rather than a home-made copy loop in insertCell() too.
Avoid unnecessary (no-op) calls to sqlite3DbFree() from sqlite3VdbeMemRelease().