Feature Request: Option to keep calendar in local folder

[severoraz]

Maybe this is against the idea of having a calendar only be accessible from the phone, but I think it would be a good idea to be able to keep calendar files in local folders on the phone.
The reason is that some users would like to synchronize their calendar with their computers too, or their office even. Using this app with this feature, plus a file syncing service like dropbox, such feat could be accomplished.