Sign in option was added
Writer and Reader were changed to Object version
Unnessecary method was removed
SQL script was added
Classes diagramm was changed
Merge branch 'userSignIn'

Conflicts:
	classesdiagramm/networkChatFirstVersion.png
	src/main/java/ua/khvorov/client/ClientSocketThread.java
	src/main/java/ua/khvorov/repositories/ClientSocketToNickRepository.java
	src/main/java/ua/khvorov/server/Server.java