Updated error codes

Biggest changes are in error codes. Since no one has net obtained a
copy of this code, I can get away with major changes (sorry!).

Since sqlite provides it’s own error codes, I have migrated my error
codes to line up with the native ones.

BIG NOTE: Error codes are now under SF_CODES::ERRORS, not
SF_CODES::ERROR. I made this change to ensure there are no name
collisions with the “ERROR = 0” enum.

Enjoy!