Wikitextparser

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- Fixed a bug in ``plain_text`` method, not handling self-closing tags correctly.

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- Fixed a bug that was causing the parser to hang when parsing complicated nested tags.

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- Fixed the order of items in ``WikiList.fullitems``. (72)
- Fixed and improved a few edge cases in ``Table.caption``. (pr 81)
- Fixed handling of external links within definition lists. (pr 83)
- Fixed a bug in parsing extension tags. (90)

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- MW variables are now recognized recognized as parser functions, not templates. (69)
- Fixed a bug in mutation of root element when a child was mutated. (66)
- Fixed a bug that was causing templates like ``{{NAMESPACE|2}}`` to be detected as a parser function. It is a template if the first argument starts with a ``:``.
- Fixed bugs in detecting attributes of table cells. (71, 73)
- Fixed a bug in detecting header cells in tables. (77)
- Fixed a bug in ``get_tags`` where extension tags without attributes were not returned. (84)
- Fixed a bug in ``get_tables`` method where tables within tag extensions were not recognized (85)

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- Fixed a bug in detection parser functions without parameters. ``{{NAMESPACE}}`` used to be detected as template, but ``{{NAMESPACE:MediaWiki}}`` a parser function. Now both of them will be detected parser functions.

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- Fix a bug in detecting external links within extension tags. (65)
- Fix a few bugs ``plain_text``/``remove_markup``. (65)