Update the tclconfig files to the latest from http://core.tcl.tk/tclconfig.
Avoid passing a flags argument with the internal WAL_SYNC_TRANSACTIONS bit set when calling sqlite3OsSync().
Change README to README.md and expand it.  Remove unrelated and obsolete files.
Ensure that if the "psow=0" URI option or FCNTL_POWERSAFE_OVERWRITE file-control is used to clear the power-safe overwrite flag, extra padding frames are added to the WAL file.
Improvements to the makefile and README for MSVC.
Revise how the Tcl system encoding is handled by the test suite.
Add OP_IdxGT and OP_IdxLE as distinct opcodes.  Formerly these operations where
done using OP_IdxGE and OP_IdxLT with the P5 flag set.  But VDBE code is easier
to read with distinct opcode names.  Also change OP_SeekGe to OP_SeekGE, and
so forth, so that the capitalization is consistent.  The whole point of this
change is to improve the readability of VDBE listings.
Reduce the number of cases where it is necessary to check for NULL after
the loop terminating condition.
Seek past NULLs in a top-constrained search.  Avoid checking for NULLs in
the body of the search.