Revert "Remove support for tables."

This reverts commit f2c2f420fc4184aad32678c2b620725f3d2822d1.

Conflicts:
	examples/minimal.json
	lib/writer/text.js
[pandoc] Parse tables.
[pandoc] Format tables.
[text] Fix parsing of empty table cells.
[text] Limit width of columns in tables to 40 symbols.
[html] Format tables.
[xelatex] Correct command parameter in test.
Sel table column width in XeLaTeX example relative to text width.
[xelatex] Format tables.
[xelatex] Restrict column width.
Merge branch 'tables'