Change the default folder location for watches to removable sd card

Since Watchmaker only needs to access the this for the list view, there is no reason to have the watch files (other than the thumbnails), on the internal sd card. Since Watchmaker only accesses the individual watch files one at a time as you either go to preview mode or when syncing with the watch, any short delay in getting the files from the removable SD card would be negligible and not a nuisance.