Adding new logo: smiling diplo

doc/logo/diplo.svg

simulators/c++2/src_simulator/ServerHelpData.h

simulators/c++2/src_simulator/arch/CPU.cpp

simulators/c++2/src_simulator/arch/FPGA.cpp

simulators/c++2/src_simulator/sim/Simulator.cpp

src/main/java/remotesimulation/CommandParser.java

...teractivesimulation/JFrameTMLSimulationPanelTimeline.java

src/main/resources/help/diplodocussimulator.html

src/main/resources/help/diplodocussimulator.md

src/main/resources/ui/util/starting_logo.png

src/main/resources/ui/util/starting_logo.xcf

ttool/src/main/java/Main.java