Getting rid of the |trackLineAndColumn| simplifies the code generator
(by unifying two paths in the code).
The |line| and |column| functions currently always compute all the
position info from scratch, which is horribly ineffective. This will be
improved in later commit(s).
Both the browser and the command-line version of the benchmark suite
runner now allow users to specify a value of the |trackLineAndColumn|
option. In case of the command-line version this required a minor CLI
redesign.