jsons: set float values as float
simplify initialisation of random numbers for core objects
update Assembly
update Source, the key in JSON is "entity", not "item"
make GUI use floats for number properties
CoreObject constructor should not accept **kw

but list all the properties instead
remove not used code
add a trace output button and introduce title & description on properties
customize some default properties
default batchNumberOfUnits to 90
Only display 2 digit for exit stat
do not change font size when zooming in or out
Make name and id of new elements configurable
open dialog on double click
remove obsolete comment