Added option to customize Pinned folder location

Items can be pinned to directories that require administative privileges
(such as Open-Shell's default installation directory), so long as users
take ownership of the pinned folder. Also adds a command to Open-Shell's
context menu that opens the current pinned folder.

Adds general support for directory-based settings by creating a new
setting type called TYPE_DIRECTORY which uses a new bool added to
BrowseLinkHelper, called bFoldersOnly. START_MENU_PINNED_ROOT
has been removed, and all instances of both it and BrowseLinkHelper
have been adjusted accordingly. To create your own directory-based
settings, use CSetting::TYPE_DIRECTORY. Empty directory paths are
reset to their default value as they can cause unexpected behavior.

Src/StartMenu/StartMenuDLL/resource.h

@@ -778,6 +778,8 @@
 #define IDS_ITEM_LINKS_TIP              3681
 #define IDS_OPEN_TRUE_PATH              3682
 #define IDS_OPEN_TRUE_PATH_TIP          3683
+#define IDS_PINNED_PATH                 3684
+#define IDS_PINNED_PATH_TIP             3685
 #define IDS_STRING7001                  7001
 #define IDS_STRING7002                  7002
 #define IDS_STRING7003                  7003