odkr: 'Open Data Kit' ('ODK') R API

Utility functions for working with datasets gathered using 'Open Data Kit' ('ODK') . These include an API to interface with 'ODK Briefcase', a 'Java' application for fetching and pushing 'ODK' forms and their contents, that allows pulling of data from either a remote 'ODK Aggregate Server' or a local 'ODK' folder, a rename function to give more human readable variable names for 'ODK' datasets, a merge function to create a single dataframe from a nested 'ODK' dataset and an expand function to disaggregate multiple choice answers that have been collapsed into single code by 'ODK'.