Load bandplans and colormaps from user directories in additional to the system ones.

[Rua]

Currently the resource directory seems to default to /usr/share/sdrpp, and SDR++ will only read resources like bandplans from there. But this is a system-wide root-owned directory. Would it be possible to support multiple resource directories, so that both the system directory and ~/.config/sdrpp are used? Then it would allow users to create their own custom bandplans without messing with the system files.

[AlexandreRouma]

It's planned