* Add TIME_IN_INTERVAL SQL operator.
The operator is implemented as a convertlet rather than an
OperatorConversion, because this allows it to be equivalent to using
the >= and < operators directly.
* SqlParserPos cannot be null here.
* Remove unused import.
* Doc updates.
* Add words to dictionary.
* refactor and link fixes
* add sql docs to left nav
* code format for needle
* updated web console script
* link fixes
* update earliest/latest functions
* edits for grammar and style
* more link fixes
* another link
* update with #12226
* update .spelling file