Adding gaussian distribution law to time intervals

src/main/java/avatartranslator/AvatarTransition.java

.../directsimulation/AvatarSimulationPendingTransaction.java

src/main/java/myutil/MyMath.java

src/main/java/ui/window/JDialogAvatarTransition.java

ttool/src/test/java/myutil/MyMathTest.java