Issue #80 - reinstated unified building for some large chunks of our code.

This should reduce compile complexity saving time and reducing linker stress.

netwerk/cache2/moz.build

@@ -20,8 +20,7 @@ EXPORTS += [
     'CacheStorageService.h',
 ]
 
-SOURCES += [
-    'AppCacheStorage.cpp',
+UNIFIED_SOURCES += [
     'CacheEntry.cpp',
     'CacheFile.cpp',
     'CacheFileChunk.cpp',
@@ -43,6 +42,11 @@ SOURCES += [
     'OldWrappers.cpp',
 ]
 
+# AppCacheStorage.cpp cannot be built in unified mode because it uses plarena.h.
+SOURCES += [
+    'AppCacheStorage.cpp',
+]
+
 LOCAL_INCLUDES += [
     '/netwerk/base',
     '/netwerk/cache',