Change Details

`mwparserfromhell` includes a tokenizer of wikitext, with a cython version for efficiency. A mandatory dependency will allow `extract_templates_and_params_regex` and `_ETP_REGEX` to be removed, and will mean the result from extract_templates_and_params will be consistent on all platforms. There was a mandatory dependency on mwparserfromhell for unix, however it was made completely optional in {T78378} due to v0.4 (2015-05-24) failing to install on Python 3.5 as was discussed at T68010#1306226. I believe this is still not fixed. We hope to re-enable Python 3.5 builds soon in {T106224}, but they might be allowed-failures.