Add check that fc_download_data() has not already downloaded current version of file
Allow forcing an update in fc_download_data(), even if the headers match
Improve update argument for fc_download_data() and rename to overwrite
Update load_si_data() to reflect changes to fc_download_data()
Add description of relevant package option to fc_download_data()
Merge pull request #31 from ajdm/check_download_data

Check if fc_download_data has already downloaded the file before downloading