Fix sync issues with large post counts and max input vars #377
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This will fix menu order issues on large page trees. If a server has a low
max_input_vars, or if a page tree is very large, the sync fails. This change will split the sync process into multiple ajax requests.I set the 'chunk' size to 200 as it seemed good in testing (high enough not to impact small-ish sites, but low enough to work on most servers).
I have tested the changes in production on large and small sites with different structures, but please let me know if you notice any issues.