Implemented CN-Heavy algo, Algo tests and fixed n-loop variants (#86)

* Debouncing of connection retry when connecting donation server fails
* When PoW variant is set on proxy, it will overrule local set PoW
* Implementation of cn_heavy algo
* Added self test for cn-heavy
* Fixed n-loop variant of powV2 and cn-heavy
* Fixed n-loop variant of powV2 and added cn-heavy for ARM
* Fixing n-loop for arm
* Limited cn-heavy to max hashfactor 3 on higher seltest fails.
* Removed a lot of casts
* Fixed algo selftest

src/net/strategies/DonateStrategy.h

@@ -62,6 +62,7 @@ private:
     void suspend();
 
     static void onTimer(uv_timer_t *handle);
+    static void onSuspendTimer(uv_timer_t *handle);
 
     bool m_active;
     Client *m_client;