Fix #8841 (broken localization support for 3rd-party apps).

* made private Catalog.h header public by moving it to 
  os/locale/tools/CollectingCatalog.h
* reintroduce B_COLLECTING_CATKEYS define (which is expected to be set
  during a collectcatkeys session) in order to decide whether or not
  to automatically include the CollecingCatalog.h header from Catalog.h
* adjust jam rule for collecting catalog keys accordingly

build/jam/LocaleRules

@@ -17,11 +17,7 @@ rule ExtractCatalogEntries target : sources : signature : regexp
 		defines = $(DEFINES) ;
 		headers = $(HAIKU_CONFIG_HEADERS) $(SEARCH_SOURCE) $(SUBDIRHDRS)
 			$(HDRS) ;
-			
+		sysHeaders = $(SUBDIRSYSHDRS) $(SYSHDRS) ;
-		# insert specific header folder containing the Catalog.h that should be 
-		# used when collecting the catalog keys:
-		sysHeaders = [ FDirName $(HAIKU_TOP) headers private locale collecting ]
-			$(SUBDIRSYSHDRS) $(SYSHDRS) ;
 
 		if $(PLATFORM) = host {
 			sysHeaders += $(HOST_HDRS) ;
@@ -71,7 +67,8 @@ rule ExtractCatalogEntries target : sources : signature : regexp
 actions ExtractCatalogEntries1
 {
 	$(HOST_ADD_BUILD_COMPATIBILITY_LIB_DIR)
-	cat "$(2[2-])" | $(CC) -E $(CCDEFS) $(HDRS) - > "$(1)".pre
+	cat "$(2[2-])" \
+		| $(CC) -E $(CCDEFS) -DB_COLLECTING_CATKEYS $(HDRS) - > "$(1)".pre
 	$(2[1]) $(HAIKU_CATALOG_REGEXP) -s $(HAIKU_CATALOG_SIGNATURE) \
 		-w -o "$(1)" "$(1)".pre
 }

headers/os/locale/Catalog.h

@@ -86,6 +86,13 @@ private:
 	// Tip: Use a descriptive name of the class implemented in that
 	//		source-file.
 
+#ifdef B_COLLECTING_CATKEYS
+
+// pull in all the macros used when collecting catalog keys.
+#include <tools/CollectingCatalog.h>
+
+#else
+
 // Translation macros which may be used to shorten translation requests:
 #undef B_TRANSLATE
 #define B_TRANSLATE(string) \
@@ -172,7 +179,7 @@ private:
 #undef B_TRANSLATE_MARK_SYSTEM_NAME_VOID
 #define B_TRANSLATE_MARK_SYSTEM_NAME_VOID(string)
 
-// Translation macros which do not let collectcatkeys try to collect the key
+// Translation macros which cause collectcatkeys to ignore this key
 // (useful in combination with the marking macros above):
 #undef B_TRANSLATE_NOCOLLECT
 #define B_TRANSLATE_NOCOLLECT(string) \
@@ -194,6 +201,8 @@ private:
 #define B_TRANSLATE_NOCOLLECT_SYSTEM_NAME(string) \
 	B_TRANSLATE_SYSTEM_NAME(string)
 
+#endif	/* B_COLLECTING_CATKEYS */
+
 #endif	/* B_AVOID_TRANSLATION_MACROS */
 
 

headers/os/locale/tools/CollectingCatalog.h

@@ -2,16 +2,11 @@
  * Copyright 2012, Haiku, Inc.
  * Distributed under the terms of the MIT License.
  */
-#ifndef _COLLECTING_CATALOG_H_
+#ifndef _TOOLS_COLLECTING_CATALOG_H_
-#define _COLLECTING_CATALOG_H_
+#define _TOOLS_COLLECTING_CATALOG_H_
-
-
-#include_next <Catalog.h>
 
 
 // Translation macros used when executing collectcatkeys
-#undef B_TRANSLATION_CONTEXT
-
 #undef B_TRANSLATE
 #define B_TRANSLATE(string) \
 	B_CATKEY((string), B_TRANSLATION_CONTEXT)