Added a file called gvctrl.go which holds all exported functions, including Set,
and the options available for use with Set. This file also holds important consts
and the settings struct. Also added a file called request.go, which houses 3
functions that are in charge of creating HTTP requests, firstly to get the log in
page from which a log in request body can be generated, then to submit the generated
log in request body, and then to submit the settings. Finally a utils.go file has
been added to house a few helper functions.