GPS Logger for Android

Invalid date

* Removed contact permission requirement - Google Drive doesn't need it any more!
* Added %DATE parameter for custom URL
* Separated satellite and network location listeners into own preference items
* Added message in log view when file is sent
* Added exponential backoff to OpenStreetMap upload
* Removed filepicker, allow user to enter directory for logs directly. Same for SFTP private key. This is to retain compatibility across Android versions and also to help SD card users