add "junk path" -k option to aapt

Adds a "junk path" option to aapt so that you can do:

   aapt add -k archive.zip path/to/some.file

and have the file stored in the zip under the name "some.file"
(without the path).  Needed so that we can use 'aapt add' in place of
'zip -j' when building jar files, which will lead to smaller
incremental OTAs.
diff --git a/tools/aapt/Command.cpp b/tools/aapt/Command.cpp
index 4742341..1a536d6 100644
--- a/tools/aapt/Command.cpp
+++ b/tools/aapt/Command.cpp
@@ -848,7 +848,7 @@
                 printf("uses-feature:'android.hardware.camera'\n");
                 printf("uses-feature:'android.hardware.camera.autofocus'\n");
             }
-            
+
             if (hasMainActivity) {
                 printf("main\n");
             }
@@ -997,8 +997,15 @@
             printf(" '%s'... (from gzip)\n", fileName);
             result = zip->addGzip(fileName, String8(fileName).getBasePath().string(), NULL);
         } else {
-            printf(" '%s'...\n", fileName);
-            result = zip->add(fileName, bundle->getCompressionMethod(), NULL);
+            if (bundle->getJunkPath()) {
+                String8 storageName = String8(fileName).getPathLeaf();
+                printf(" '%s' as '%s'...\n", fileName, storageName.string());
+                result = zip->add(fileName, storageName.string(),
+                                  bundle->getCompressionMethod(), NULL);
+            } else {
+                printf(" '%s'...\n", fileName);
+                result = zip->add(fileName, bundle->getCompressionMethod(), NULL);
+            }
         }
         if (result != NO_ERROR) {
             fprintf(stderr, "Unable to add '%s' to '%s'", bundle->getFileSpecEntry(i), zipFileName);