stopwords file for spanish language.
Added function read_lines which reads a text file and returns the resulting array of stacking its lines.
stopwords file is configured in settings.json file and read from sandbox module.
init sandbox variables from server bootstrap init function.
new stopwords_file parameter.
Fixed test extract_keywords, new server setting stopwords_file added.
added word:de
newop can be followed by add_constraint and add_plugin_in/mid/out in a cascade style programming.
minor change returning errors in sandbox pipeline