LimeRick 0.0.1 beta

• adding two experimental functions allowing passive measurements and monitoring usage of the package (lsAddPackageStats(), lsGetPackageStats())
• adding low- and high-level functions for adding responses directly from R (lsAddResponse(), lsAddFeedback())
• lsGetResponses() for importing into R survey responses directly from LimeSurvey
• lsGetSummary() for summarize responses for a survey (complete, incomplete, all)
• lsGetAnswerOption() for listing options available for a given answer
• lsGetProperties() for getting properties of a survey or a question
• lsList() for listing surveys, groups, and questions
• lsSessionCache environment for storing session keys
• lsSessionKey() function for obtaining and releasing LimeSurvey session key
• lsAPI() low-level function for LimeSurvey Remote Control API calls end error handling