hpkg format: Generalize user/global settings file attributes

* For all identifiers: Rename global settings file to global writable
  file. We want to use the respective attribute also for other writable
  files, not only settings files.
* User settings file/global writable file info/attribute: Add
  isDirectory property/child attribute. This allows declaring global/
  user settings directories associated with the package.

headers/os/package/UserSettingsFileInfo.h

@@ -25,19 +25,25 @@ public:
 										infoData);
 								BUserSettingsFileInfo(const BString& path,
 									const BString& templatePath = BString());
+								BUserSettingsFileInfo(const BString& path,
+									bool isDirectory);
 								~BUserSettingsFileInfo();
 
 			status_t			InitCheck() const;
 
 			const BString&		Path() const;
 			const BString&		TemplatePath() const;
+			bool				IsDirectory() const;
 
 			void				SetTo(const BString& path,
 									const BString& templatePath = BString());
+			void				SetTo(const BString& path,
+									bool isDirectory);
 
 private:
 			BString				fPath;
 			BString				fTemplatePath;
+			bool				fIsDirectory;
 };