Manage sdcard content better #82
Description
Sdcards are HUGE nowadays, so let's not optimise storage capacity. No need for that.
That allows to have the radio use a directory as curdir, instead of the root. Than we can switch between firmware versions on the radio, by keeping different folders for different firmware versions.
This also allows for non_version specific folders for non_version related content, such as named voice files, images, log files and model note files.
Finally, this would also allow for radio type specific folders, so we would have one sdcard content set only for all radios, that is automatically supporting backwards compatibility by just including the folder structure and content for versions over time.
Also, predefined templates to be used for easily restoring model files adapted for radio specific configurations would become possible.
One to rule them all...