* Support {equation}, {equation*}, and {split}
* Update screenshots
* Allow {split} at top level
* Move equation column number check to to ParseArray
* Add token to ParseError
* Sharpen parameters passed to parseArray
* Add token information
* Update an {array} spec in screenshotter
* Adjust {array} screenshotter spec
* Make a non-strict error call when {array} argument specifies too few columns.
* Move context checks to a helper function.
