Draft: Add dumb terminal emulation
A dumb terminal has only one control sequence: \r which moves the cursor to the start of the next line.
Profile option Emulation
selects which emulation to use. Any value other than dumb
selects the standard Vt102 emulation.
A dumb terminal might not be very useful, but it still may have some uses. This code might be useful in considering Konsole emulation design. Having a second Emulation subclass can make it clearer to see which methods belong in Emulation class and which in subclasses.
A discussion here may be considered related to !593 (merged), and started by my last comment in !615 (closed).