Modernize C++ usage (#144)

* Stratosphere: Use modern C++ idioms in some places

* algorithms like std::for_each are used instead of raw loops

* Stratosphere: Replace more raw loops with algorithms

* Stratosphere: Add a utility predicate function to test for equality with a reference element

This can be used to rewrite some common raw loops using algorithms instead

* fs.mitm: Use variant

* fs.mitm: Use enum class

* fs.mitm: Turn RomFSSourceInfo::Cleanup into a destructor

This obsoletes the need for a custom deleter in other places

* fs.mitm: Use enum class some more

* fs.mitm: Use unique_ptr

* fs.mitm: Simplify initialization

* Stratosphere: Simplify initialization

* fs.mitm: Use unique_ptr (fix memory leak along the way)

The previous code was using "delete" rather than "delete[]"

* fs.mitm: Use vector::emplace_back rather than push_back

emplace_back constructs elements in-place, hence avoiding a redundant element copy.

* Stratosphere: Replace more raw loops with algorithms

* Stratosphere: Use unique_ptr

* fs.mitm: Replace more raw loops with algorithms

* Stratosphere: Prefer move-construction over copy-construction when moving sink parameters around

stratosphere/fs_mitm/source/imitmserviceobject.hpp

@@ -9,10 +9,10 @@
 class IMitMServiceObject : public IServiceObject {
     protected:
         Service *forward_service;
-        u64 process_id;
-        u64 title_id;
+        u64 process_id = 0;
+        u64 title_id = 0;
     public:
-        IMitMServiceObject(Service *s) : forward_service(s), process_id(0), title_id(0) {
+        IMitMServiceObject(Service *s) : forward_service(s) {
             
         }
         
@@ -22,7 +22,7 @@ class IMitMServiceObject : public IServiceObject {
                 
         virtual void clone_to(void *o) = 0;
     protected:
-        virtual ~IMitMServiceObject() { }
+        virtual ~IMitMServiceObject() = default;
         virtual Result dispatch(IpcParsedCommand &r, IpcCommand &out_c, u64 cmd_id, u8 *pointer_buffer, size_t pointer_buffer_size) = 0;
         virtual void postprocess(IpcParsedCommand &r, IpcCommand &out_c, u64 cmd_id, u8 *pointer_buffer, size_t pointer_buffer_size) = 0;
         virtual Result handle_deferred() = 0;