logic: Ask user before reparsing the project

While the message box with the question is visible the ui is blocked. A message appears when:
* when project was edited
* when preferences were edited
* when project file has more recent changes than db
* when db has a different version than Coati

src/lib/Project.h

@@ -13,15 +13,25 @@ class StorageAccessProxy;
 class Project
 {
 public:
+	enum ProjectState
+	{
+		PROJECT_NONE,
+		PROJECT_EMPTY,
+		PROJECT_LOADED,
+		PROJECT_OUTDATED,
+		PROJECT_OUTVERSIONED
+	};
+
 	static std::shared_ptr<Project> create(StorageAccessProxy* storageAccessProxy);
 
 	~Project();
 
 	const FilePath& getProjectSettingsFilePath() const;
 
-	bool load(const FilePath& projectSettingsFile);
+	ProjectState load(const FilePath& projectSettingsFile);
+	ProjectState reload();
+
 	bool save(const FilePath& projectSettingsFile);
-	void reload();
 
 	void clearStorage();
 
@@ -35,17 +45,19 @@ private:
 	void parseCode();
 
 	void setProjectSettingsFilePath(const FilePath& path);
+	void loadStorage(const FilePath& path);
 	void updateFileManager();
 
 	Parser::Arguments getParserArguments() const;
 
 	StorageAccessProxy* const m_storageAccessProxy;
 
+	ProjectState m_state;
+
 	FilePath m_projectSettingsFilepath;
 	FileManager m_fileManager;
 
 	std::shared_ptr<Storage> m_storage;
-	bool m_storageWasLoaded;
 };
 
 #endif // PROJECT_H