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
{
    std::vector< std::vector<std::string> > stack;
    stack.push_back(std::vector<std::string>());
    enum CmdParseState
    {
        STATE_EATING_SPACES,
        STATE_EATING_SPACES_IN_ARG,
        STATE_EATING_SPACES_IN_BRACKETS,
        STATE_ARGUMENT,
        STATE_SINGLEQUOTED,
        STATE_DOUBLEQUOTED,
        STATE_ESCAPE_OUTER,
        STATE_ESCAPE_DOUBLEQUOTED,
        STATE_COMMAND_EXECUTED,
        STATE_COMMAND_EXECUTED_INNER
    } state = STATE_EATING_SPACES;
    std::string curarg;