Recommend the following changes to src/delta_format.wiki

1. Revert the output of the unified diff to its oldest original (delta_format.html, not .wiki) form in artifact/403bbf0aac. As it is computer generated output, the two 'decendent' typos should never have been spell-corrected (the point of the diff is to show the spelling error being corrected by a delta).

2. The checksum computed by src/delta.c/checksum() is actually modulo 2^32, not modulo 2^32 - 1.

3. The base-64 encoding is not identical to any described in the RFC; Fossil's encoding uses a different alphabet starting at '0' rather than 'A' as in the RFC.

4. typo s/This is there the/This is where the/

I can supply a patched copy of the file if you would like.