System.in and console command

Now, System.in can be used transparently by commands. I have tested with the mauve-filter command and that works well.

In theory, System.setIn can be used for different commands independantly (one System.in per Thread with inheritence) and also piped ('|') commands ... but I haven't tested that.

The console command also works and I successfully run commands under a new console and came back to the first one and typed other commands