Solver manager

Because of #142 (closed) I can't write a proper markdown-based description thus I upload a screenshort ...

• remove former StateBlock notification list
• StateBlock::getState returns by copy
• remove StateBlock::getPtr

src/state_block.h

@@ -105,9 +105,9 @@ public:
          **/
         void unfix();
 
-        bool hasLocalParametrization();
+        bool hasLocalParametrization() const;
 
-        LocalParametrizationBasePtr getLocalParametrizationPtr();
+        LocalParametrizationBasePtr getLocalParametrizationPtr() const;
 
         void setLocalParametrizationPtr(LocalParametrizationBasePtr _local_param);
 
@@ -192,12 +192,12 @@ inline void StateBlock::unfix()
     fixed_ = false;
 }
 
-inline bool StateBlock::hasLocalParametrization()
+inline bool StateBlock::hasLocalParametrization() const
 {
     return (local_param_ptr_ != nullptr);
 }
 
-inline LocalParametrizationBasePtr StateBlock::getLocalParametrizationPtr()
+inline LocalParametrizationBasePtr StateBlock::getLocalParametrizationPtr() const
 {
     return local_param_ptr_;
 }