(rasqal_new_query_results_from_string): Added
(rasqal_new_query_results_from_string): Guess formatter from data

If @formatter is NULL guess it using input data via
rasqal_world_guess_query_results_format_name()
(rasqal_new_query_results_from_string): Always guess formatter from data

Remove formatter arg.
(rasqal_new_query_results_from_string): Make string_len optional.
Add result format guessing from data for csv and tsv

(rasqal_query_results_sv_score_first_line): Added.

(rasqal_query_results_csv_recognise_syntax,
rasqal_query_results_tsv_recognise_syntax): Added using filename
suffix and rasqal_query_results_sv_score_first_line() to guess based
on first line of content.
Merge branch 'master' into results-compatible