title: Support for selection of kaa application key during execution
body: <p>I am making multiple clients accessing same Kaa application. Consider it as fork of a process. As I can understand, Kaa server differentiate b/w clients based on the hash which is part of kaa public key. So essentially, for having multiple clients, I should be having multiple kaa public-private keys generated.
  Now, questions comes here. As by default this key is taken by default and there is no option to select key for an application (if I haven't missed any such update), how can we achieve it. I can add same support within Kaa SDK at client side but I am afraid if any future update will make my code void or there will be effort needed to maintain my code during Kaa version upgrade.</p>
  
  <p>Touching Kaa SDK is my last option, so is there any way Kaa could differentiate b/w clients?</p>