Implemented notes from last pull request; added layout changes

Modified StartActivity to launch the StartGPS method only if the take picture button is pressed. If the GPS is off, an alert dialog is launch edand it will not allow the user to take a picture unless  the GPS on. Also if the picture is taken from camera, then the longitude and latitude is added into a EditText field in the FormActivity but it cannot be edited. However if the user grabs the picture from gallery then the user can add the coordinates themselves. We also made minor layout changes on activity_start.xml and lowered API to enable compatibility with older devices.