Tables and rows now use newline as padding

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.
Updated row and table handling

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.
fixed hacky table cell style exception, added tests

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.
Reorder table tokenizer methods for forward declaration

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.
Add padding to table cell tags

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

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

Fix problem in which invalid table attributes were being parsed
incorrectly. Added tests.
Refactor methods to avoid returning tuples

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.
All tokenizer end methods return a stack

For C compatability, switch table cell end to return the stack.
Now context is kept by using `keep_context` when calling `self._pop()`.
Use uint64_t for context

For the C tokenizer, include `<stdint.h>` and use `uint64_t` instead
of `int` for context. Changes to tables mean that context can be
larger than 32 bits, and it is possible for `int` to only have 16
bits anyways (though this is very unlikely).
Implement CTokenizer for tables

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.