Remove B_COMMON*_DIRECTORY and kCommon*Directory constants

* This does intentionally break source compatibility, so that a review
  of concerned code is forced.
* Binary compatibility should be maintained in most cases. The values
  of the constants for the writable directories are now used for the
  writable system directories. The values for the non-writable
  directories are mapped to "/boot/system/data/empty/...", an empty or
  non-existent directory, so that they will simply be skipped in search
  paths. Only code that explicitly expects to find something in a
  B_COMMON_* directory, will fail.

headers/os/storage/FindDirectory.h

@@ -33,32 +33,15 @@ typedef enum {
 	B_SYSTEM_PACKAGES_DIRECTORY,
 	B_SYSTEM_HEADERS_DIRECTORY,
 
-	/* Common directories, shared among all users. */
-	B_COMMON_DIRECTORY					= 2000,
-	B_COMMON_SYSTEM_DIRECTORY,
-	B_COMMON_ADDONS_DIRECTORY,
-	B_COMMON_BOOT_DIRECTORY,
-	B_COMMON_FONTS_DIRECTORY,
-	B_COMMON_LIB_DIRECTORY,
-	B_COMMON_SERVERS_DIRECTORY,
-	B_COMMON_BIN_DIRECTORY,
-	B_SYSTEM_ETC_DIRECTORY,
-	B_COMMON_DOCUMENTATION_DIRECTORY,
-	B_SYSTEM_SETTINGS_DIRECTORY,
-	B_COMMON_DEVELOP_DIRECTORY,
-	B_SYSTEM_LOG_DIRECTORY,
+	B_SYSTEM_ETC_DIRECTORY				= 2008,
+	B_SYSTEM_SETTINGS_DIRECTORY			= 2010,
+	B_SYSTEM_LOG_DIRECTORY				= 2012,
 	B_SYSTEM_SPOOL_DIRECTORY,
 	B_SYSTEM_TEMP_DIRECTORY,
 	B_SYSTEM_VAR_DIRECTORY,
-	B_COMMON_TRANSLATORS_DIRECTORY,
-	B_COMMON_MEDIA_NODES_DIRECTORY,
-	B_COMMON_SOUNDS_DIRECTORY,
-	B_COMMON_DATA_DIRECTORY,
-	B_SYSTEM_CACHE_DIRECTORY,
-	B_COMMON_PACKAGES_DIRECTORY,
-	B_COMMON_HEADERS_DIRECTORY,
+	B_SYSTEM_CACHE_DIRECTORY			= 2020,
 
-	B_SYSTEM_NONPACKAGED_DIRECTORY,
+	B_SYSTEM_NONPACKAGED_DIRECTORY		= 2023,
 	B_SYSTEM_NONPACKAGED_ADDONS_DIRECTORY,
 	B_SYSTEM_NONPACKAGED_TRANSLATORS_DIRECTORY,
 	B_SYSTEM_NONPACKAGED_MEDIA_NODES_DIRECTORY,