Pytablewriter

- Add escape processing for vertical bar characters in Markdown table items to get consistent rendering result

- Add a table writer class for space aligned values
- Add default headers for Markdown/SQLite table writers that used when headers are null
- Change to preserve spaces in table items
- Change to remove line breaks from headers for text table formats
- Make headers are not mandatory for Pandas writer
- Modify Markdown output format to get more consistent rendering result
- Improve output consistency for SQLite

- Add support for LaTeX table/matrix
- Improve real number output precision.for CSV/JSON/LTSV/TOML/TSV

- Add `NumPy` writer class
- Add `search_table_format` method to `TableFormat` class
- Add attributes to pandas writer class: `import_pandas_as`/`import_numpy_as` to specify import name
- Modify to sanitize `Elasticsearch` index name
- Bug fixes

- Fix the case that incorrect write result when matrix which has uniform size for each row

- Add support for Elasticsearch
- Simplify pandas dataframe output
- Change to accept non string values as headers
- Modify log messages
- Bug fixes