Cherry-pick the SQLITE_DIRECT_OVERFLOW_READ fix for ticket
[ac0ff496b7e3] of changes [c5256b59ad] and [c723e3e18a] 
into the nx-devkit branch.
Cherry-pick the fix to surplus overflow files in the multiplexor,
check-in [1238619756c0c] in the trunk.
Cherrypick the fix from [629108c8e5376f989] into the nx-devkit branch.
Cherrypick the FTS fix in [c05c3fd0d] into the nx-devkit branch.
Ticket [edb497982c].
Do not rely on the _WIN32_WINNT macro as vs2005 does not define it by default.
Instead, always assume winNT unless the makefile explicitly sets
SQLITE_OS_WINNT=0.
Port the command-line shell enhancements including the new --cmd option
to the nx-devkit branch.
In the multiplexor extension, improve the error logging when a chunk fails
to open.
Fix the multiplexor logging so that it works with SQLITE_ENABLE_8_3_NAMES.