It's a new debug key, and it's framed by the #ifndef NDEBUG directive, so it's only enabled for debug versions of Oolite.
And yes, its only purpose is to get Oolite to connect/disconnect to a running console, if: debug.oxp/basic-debug.oxp was found in the addons directory, and you've got a running tcp debug console.
If running mac Oolite, the integrated mac debug console doesn't have connection issues, so mac integrated consoles are unaffected by pressing c when paused during flight.
Of course, console support itself is only enabled for debug versions of Oolite too!
Just to recap, starting from 1.77, the main release version of Oolite will be without debug features, making it faster, and using less memory than the otherwise identical debug version. The debug version will also be available, with all the debug features exactly as they are on the nightly builds.
Hmm, maybe we'll need 2 different keymaps, one for each version. What do you reckon?
Anyway, I've had another look at the various macro commands, and found a SNAFU in rev3909 that meant using :resetM would make it impossible to manually create new macros on a mac, and since rev4807 made it impossible to create new macros on windows & linux pcs too!
The new :resetM is now in trunk and - since I was fiddling with that part of the code - I've re-tweaked the new :listM so it lists all the built-in (& oxp) macros first - in alphabetical order, then all the user defined ones, again in alphabetical order. Hope that this last way of listing the macros makes a bit of sense!
Oh, and a heads-up: it looks like I'm going to do a bit more testing on all this debug console related stuff, so there might be yet another version of debug console in a while...
PS: I was 'slightly' distracted by the day job as I wrote this post, and I kind-of overused 'and yes' in about everywhere. Re-reading it, I didn't like the overall tone of this post. This post is now new, improved, with 90% less 'and yes'ses, and suitable for human usage!