fixed a segfault caused by formula ai self-reference-counting quirks,

...plus removed some accidential whitespace.

src/ai/ai.cpp

@@ -243,6 +243,7 @@ ai_default::ai_default(ai::readwrite_context &context) :
 	recruiting_preferred_(0),
 	formula_ai_(NULL)
 {
+	add_ref();
 }
 
 ai_default::~ai_default(){

src/ai/contexts.hpp

@@ -71,7 +71,6 @@ public:
 
 	virtual side_context& get_side_context() = 0;
 	virtual int get_recursion_count() const = 0;
-	
 };
 
 class readonly_context;

src/ai/formula_ai.cpp

@@ -1623,6 +1623,7 @@ formula_ai::formula_ai(ai::readwrite_context &context) :
 	function_table(*this),
 	candidate_action_manager_()
 {
+	add_ref();
 }
 
 void formula_ai::handle_exception(game_logic::formula_error& e) const