Merge pull request #4 from ftl/3-add-support-for-multiple-connections

3 add support for multiple connections

upgrade dependencies

update to go 1.18, update the rigproxy

add a button that acts like a MQTT switch, e.g. to control some IoT d…

…evices

add grace period between changing the mode and setting the filter band

update docu

build a binary deb package instead of a source package - life is way …

…too short for all this hassle!