Reviewed by Dumitru Daniliuc.

        Add idl and mock implementation for HTML5 FileSystem API
        https://bugs.webkit.org/show_bug.cgi?id=43134

        Add idl for: FileSystem (as DOMFileSystem), Entry, Flags, Metadata,
        FileSystemCallback, EntryCallback and ErrorCallback.
        http://dev.w3.org/2009/dap/file-system/file-dir-sys.html

        They are added only for Mac and chromium.

        Tests will be added when we expose the entry point and add implementation.

        * DerivedSources.make:
        * WebCore.gypi:
        * WebCore.xcodeproj/project.pbxproj:

        * storage/DOMFileSystem.cpp: Added.
        * storage/DOMFileSystem.h: Added.
        * storage/DOMFileSystem.idl: Added.
        * storage/Entry.cpp: Added.
        * storage/Entry.h: Added.
        * storage/Entry.idl: Added.
        * storage/EntryCallback.h: Added.
        * storage/EntryCallback.idl: Added.
        * storage/ErrorCallback.h: Added.
        * storage/ErrorCallback.idl: Added.
        * storage/FileSystemCallback.h: Added.
        * storage/FileSystemCallback.idl: Added.
        * storage/Flags.h: Added.
        * storage/Flags.idl: Added.
        * storage/Metadata.h: Added.
        * storage/Metadata.idl: Added.
        * storage/MetadataCallback.h: Added.
        * storage/MetadataCallback.idl: Added.

        * bindings/scripts/CodeGenerator.pm: Added special case handlings for generating setter/getter names for CREATE/EXCLUSIVE attributes in Flags.idl.

        * bindings/scripts/test/TestObj.idl: Updated.
        * bindings/scripts/test/CPP/WebDOMTestObj.cpp: Updated.
        * bindings/scripts/test/CPP/WebDOMTestObj.cpp: Updated.
        * bindings/scripts/test/CPP/WebDOMTestObj.h: Updated.
        * bindings/scripts/test/GObject/WebKitDOMTestObj.cpp: Updated.
        * bindings/scripts/test/GObject/WebKitDOMTestObj.h: Updated.
        * bindings/scripts/test/JS/JSTestObj.cpp: Updated.
        * bindings/scripts/test/JS/JSTestObj.h: Updated.
        * bindings/scripts/test/ObjC/DOMTestObj.h: Updated.
        * bindings/scripts/test/ObjC/DOMTestObj.mm: Updated.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@64414 268f45cc-cd09-0410-ab3c-d52691b4dbfc