UMD exceptions

[pjanevskiTT]

At the moment, UMD handles a lot of errors either through log_assert or throwing runtime_error. Log assert produces the print on the screen because it comes with a fatal print by desing, which UMD clients don't always want to see. Part of the log_assert messages are removed in #516. Other log_assert messages are not removed at the moment since some of those will go away with the redesign or with new exceptions.

Proposal is to have hierarchy of exception, meaning that UMD should derive it's own exceptions, something like

class TimeoutException : public std::exception {
     int random_data;
    TimeoutException(...) : std::exception(...) {}
}

----

if (...) {
    throw TimeoutException(...);
}

so the client can catch the exception and print the message if it wants to, UMD should not behave like this by default.

This is going to be a master issue which tracks Exception work, smaller issues, which are going to be groups of proposed exceptions explained, are going to be sub-issues of this one