* Increase MAX_DEPTH to 100

* Update nested_templates_and_style_tags to cover new limit

This regression seems more severe than the bug the commit was
attempting to fix (incorrect parsing of nested wikilinks in normal
links), so that bug is reintroduced until localization-aware parsing
that allows us to detect file links is added.

This commit partially reverts fac60dee48.

* Proposed fix for https://github.com/earwig/mwparserfromhell/issues/197

* Port the fix for #197 to the C tokenizer

* Fix parsing of external links where the URL is terminated by some special character

- One existing test case has been found wrong -- current MediaWiki
  version always terminates the URL when an opening bracket is
  encountered.
- Other test cases added: double quote, two single quotes and angles
  always terminate the URL (regardless if it is a free link or external
  link inside brackets). One single quote does not terminate the URL.

* Fix case-insensitive parsing of URI schemes

Fixes #198

Co-authored-by: Ben Kurtovic <ben.kurtovic@gmail.com>

Fixes #221.

Also removed the max cycles stop-gap, allowing much more complex pages
to be parsed quickly without losing nodes at the end

Also fixes #65, fixes #102, fixes #165, fixes #183
Also fixes #81 (Rafael Nadal parsing bug)
Also fixes #53, fixes #58, fixes #88, fixes #152 (duplicate issues)

Tests were not correctly testing the situations without a table close.
Fixed tests and then fixed tokenizers for failing tests. Also refactored
pytokenizer to more closely match the ctokenizer by only holding the
`_parse` methods in the try blocks and no other code.

Python 3.4 compiles C extensions with the
`-Werror=declaration-after-statement` flag that enforces C90 more
strictly than previous versions. Move all statements after declarations
to make sure this extension builds on 3.4.

Table tags no longer self-closing. Rows and cells now contain their
contents. Also refactored out an `emit_table_tag` method.
Note: this will require changes to the Tag node and possibly the builder,
those changes will be in the next commit.

CTokenizer is completely implemented in this commit - it didn't
make much sense to me to split it up. All tests passing, memory test
shows no leaks on Linux.

For C compatability, switch table cell end to return the stack.
Now context is kept by using `keep_context` when calling `self._pop()`.

Various changes to avoid returning tuples - working on the C tokenizer
made me realize this was a bad idea for compatability/similarity between
the two.

Fix problem in which invalid table attributes were being parsed
incorrectly. Added tests.

Fix problem in which fake table closes were causing a problem inside
cells. Changed inline table handling to fix this.

Padding now included on all wiki table cells. With wiki table cells
that include attributes, `wiki_markup` is also included (unchanged).

Make sure py tokenizer methods only call methods that have been declared
earlier. Not necessary but makes it much easier to maintain/write
the C tokenizer if methods are in the same order.

Removed the `StopIteration()` exception for handling table style
and instead call `_handle_table_cell_end()` with a new parameter.
Also added some random tests for table openings.

Changed row recursion handling to make sure the tag is emitted even
when hitting recursion limits. Need to test table recursion to make
sure that works. Also fixed a bug in which tables were eating the
trailing token. Added several tests for rows and trailing tokens with
tables.

Tables and rows use newlines as padding, partly because these characters
are pretty important to the integrity of the table. They might need
to be in the preceding whitespace of inner tags instead as padding after,
not sure.

Added comments, tried to keep to 80 character lines.

Started styling attributes for table row and table start. Still not entirely
sure about this, definitely need to make changes regarding padding.

Support for header cells was mostly in already, just needed minor
changes. Added two tests as well.

Started support for parsing table style attributes. I suspect some
of this is incorrect, need to add more tests to see.

Added another stack layer for tokenizing table cells because of
styling/correctness of implementation. Added many tests cases.