CountryID               Function for creating standardised country
                        names and ID variables
DpiGet                  Downloads the Database of Political
                        Institutions (DPI)
DropNA.psData           Drop rows from a data frame with missing values
                        in the OutCountryID variable.
PolityGet               Downloads Polity IV
RRCrisisGet             Download and combine Reinhart and Rogoff's
                        (2010) crisis dummy variables into one data
                        frame
WinsetCreator           Create Winset and Selectorate variables
