It would be nice if the debug console had a little help page of itself, to describe the syntax to issue commands (also the nested ones), and a disclaimer that usage can be dangerous.

Maybe add a debug-console-only command like help that shows how to use nested commands and potentially other advanced tricks, and add 'for more information on using this console type XXX'.

See also:
- https://github.com/bitcoin/bitcoin/pull/7783#issuecomment-248274853
- https://github.com/bitcoin/bitcoin/issues/8544#issuecomment-240970925
- #8912 Console command paths cannot be specified correctly with backslashes
history.append(cmd);
        // E
        while(history.size() > CONSOLE_HISTORY)
            history.removeFirst();
        // S
        historyPtr = history.size();
        // S
        scrollToEnd();
    }
}
void RPCConsole::browseHistory(int offset)
{
    // s
    if (historyPtr == history.size()) {
        cmdBeforeBrowsing = ui->lineEdit->text();
    }
    historyPtr += offset;
    if(historyPtr < 0)
        historyPtr = 0;
    if(historyPtr > history.size())
        historyPtr = history.size();
    QString cmd;
    if(historyPtr < history.size())
        cmd = history.at(historyPtr);
    else if (!cmdBeforeBrowsing.isNull()) {
        cmd = cmdBeforeBrowsing;
    }
    ui->lineEdit->setText(cmd);
}
void RPCConsole::startExecutor()