Add mesh.setchannel

[jingman]

This adds a function, mesh.setchannel for setting the mesh channel without having to also pass a pan id and address, as are required with mesh.config.

Usage: mesh.setchannel(26) will set the mesh channel to 26.

Important: You'll want all the Scouts in your Troop to change to this new channel as well, so the practical usage should be command.all("mesh.setchannel",26).

Closes: #187

[amcjen]

looks solid to me! only caveat is that if a scout doesn't get the message, then it'll be offline until the sending scout can switch back to that channel to communicate again.

[jingman]

Indeed. Well hey, great power, great responsibility!

[matthijskooijman]

Like I already said on Slack:

Code looks good, except that I think this introduces some duplicate code. the channel argument from meshConfig should probably removed and mesh.config van just call the new function

also, there is a lot of unrelated whitespace change that clutters the diff, please configure your editor to not do that (and preferably also remove the changes from this commit).

Furthermore, you should add a Closes: #187 to the commit message so that ticket is automatically closed when merging.

[jingman]

Thanks @matthijskooijman, I've made the edits you suggested - they're in d783a6088e7e8e063a9430b3ce2e67b62e2e6457

[quartzjer]

Looks good to me!