[AndyB] Resave posts all 1.7

• Now requires running from CLI only. The closing of the board is no longer required.

Added Post ID start and Post ID end to options page.

• Now requires the following two Options to be disabled before the add-on can be run: Enable edit log display after and Enable edit history and prune after.

• Fixed issue with History link.

• Now preserves 'Last edited by' information.