Improve command config structure

[jpentland]

Currently commands are stored in two files:

• defaultconf/commands.toml
• local config dir/usercommands.toml

A better way would be to allow any arbitrary number of command configs to be imported via a dropdown box / file browser. This would allow a set of predefined configs to be shipped, set up for different games. Users could then also share their configs with others and simply add them to the list of imported configs.