#42 Option for only one instance of Contruct open at a time

[Cameron Mercer]

This would be very helpful for those of us that open and close many different .cap files in rapid succession - helpful for nothing more than organizational reasons. (Id rather manage downloaded and explorer-opened .caps from the project bar than the windows taskbar, if you can understand this :) .

So instead, every .cap you open will open in the already-loaded instance of Construct. Just a professional nicety of sorts.