Add Cocoa implementation of wxStandardPaths

Previously wxStandardPathsCF was used for all Mac builds and it used
FSFindFolder() (CoreFoundation) calls in Carbon builds, but many hard coded
values in Cocoa builds. The Cocoa implementation uses NSFileManager and
NSBundle to retrieve the folder locations from the system.

Closes https://github.com/wxWidgets/wxWidgets/pull/89

build/files

@@ -33,7 +33,6 @@ BASE_UNIX_AND_DARWIN_SRC =
     src/unix/fdiounix.cpp
     src/unix/snglinst.cpp
     src/unix/stackwalk.cpp
-    src/unix/stdpaths.cpp
     src/unix/timerunx.cpp
     src/unix/threadpsx.cpp
     src/unix/utilsunx.cpp
@@ -48,7 +47,6 @@ BASE_UNIX_AND_DARWIN_HDR =
     wx/unix/evtloop.h
     wx/unix/evtloopsrc.h
     wx/unix/pipe.h
-    wx/unix/stdpaths.h
     wx/unix/stackwalk.h
     wx/unix/tls.h
     wx/unix/fswatcher_kqueue.h
@@ -71,10 +69,12 @@ BASE_UNIX_AND_DARWIN_NOTWXMAC_HDR =
 BASE_UNIX_SRC =
     $(BASE_UNIX_AND_DARWIN_NOTWXMAC_SRC)
     src/unix/fswatcher_inotify.cpp
+    src/unix/stdpaths.cpp
 
 BASE_UNIX_HDR =
     $(BASE_UNIX_AND_DARWIN_NOTWXMAC_HDR)
     wx/unix/fswatcher_inotify.h
+    wx/unix/stdpaths.h
 
 
 ## Windows
@@ -134,7 +134,6 @@ BASE_WIN32_HDR =
 BASE_COREFOUNDATION_SRC =
     src/osx/core/cfstring.cpp
     src/osx/core/evtloop_cf.cpp
-    src/osx/core/stdpaths_cf.cpp
     src/osx/core/strconv_cf.cpp
     src/osx/core/utilsexc_base.cpp
 
@@ -164,10 +163,13 @@ BASE_OSX_SHARED_HDR =
 BASE_AND_GUI_OSX_CARBON_SRC =
     src/osx/carbon/utils.cpp
     src/osx/carbon/uma.cpp
+    src/unix/stdpaths.cpp
+    src/osx/core/stdpaths_cf.cpp
 
 BASE_AND_GUI_OSX_COCOA_SRC =
     src/osx/cocoa/utils.mm
     src/osx/cocoa/power.mm
+    src/osx/cocoa/stdpaths.mm
 
 BASE_AND_GUI_OSX_IPHONE_SRC =
     src/osx/iphone/utils.mm