Demo of basic working with arrays

Memory, links, copy
new: git-ignore file
add: autoboxing demo
add: exceptions demo
add: zoo as a basic model
new: demo for clonong operations and references
new: exception handling demo
new: hash code
new: inner-outer classes demo
new: numbers demo
new: strings demo
new: runnable demo
new: system properties demo
Merge commit 'f6441dcd0b949e07f17fa59a358099f4fadeb2ac'