Don't attempt to re-format existing command objects. Fixes #555. Fixes #722

[pjrobertson]

Who'd have thought it would be such an easy fix.

I'm not sure why we were attempting to re-creating an existing QSCommand object (in QSHistoryController.m:L49) and doing so incorrectly!

Looks like afb1023 added the objectValue method (not sure what it does, @tiennou ?)
and … good old Code Cleanup 2b08e42 is as far back as I can go for QSHistoryController.m, but looks like that didn't actually change anything.

A few other tidy ups:

• Don't know why(id) was used in QSHistoryController for - (void)addCommand:(QSCommand *)command. It's always a QSCommand so I've changed this
• If the 'last command' proxy was run, there's no point adding this command (or it's resolved command) to the catalog, the 'last command' will always be the 'last command' until a different command is run. Confusing? ;-)

[pjrobertson]

Sorry, this doesn't fix #722, which is already fixes. It semi resolves #1115 (I hope I avoided GH's automagical closing system there :D )

[pjrobertson]

And I can confirm that this does fix #905 as @skurfer suggested.

Although using the comma trick on command objects doesn't work… but that's another issue ;-)

[skurfer]

Of the things listed in #1115, what does this not fix? I now seem to be able to use Recent Commands and the Last Command proxy object. Nice work!