Make sure new sqlite3_vtab objects created by the xCreate() virtual table
method are initialized by the system, in accordance with the documentation.
Rearrange an expression in vdbemem.c to avoid a (harmless) reference to a possibly unitialized variable.
Add a four-byte prefix to the BtShared.pTmpSpace buffer to avoid reading
before the beginning of an allocation.
Fix a problem causing lock5.test to fail in mmap-mode.
Update releasetest.tcl so that x86-64 runs a superset of the x86 tests.
Merge latest trunk changes with this branch.
Fix a problem causing sqlite3changeset_concat() to fail to detect attempts to concatenate patchsets which changesets.