Simplify merges of the annotation code.

Change-Id: I9fd3b53032b2e6053094500571775ed2fb5edf78
dx.bat: Don't change directory.

Changing directory to that of dx.bat prevents dx.bat from being
used with relative directories. This leads to all sorts of
issues integrating it with build systems that expect this to
work.

I've tested that this change works under the following conditions:
1. Android SDK in a path containing spaces.
2. java.exe in a path containing spaces.
3. Java object files in a path containing spaces.
4. Output jar file in a path containing spaces.
5. Java object files specified with relative paths.
6. Java object files specified with absolute paths.
7. Output jar file specified with relative paths.
8. Output jar file specified with absolute paths.

Change-Id: I1b47a6cc73169607cc6238acf197e3b467c9bcbc
Implement the dalvik side of libcore.reflect.

(Cherry-pick of b4d5cf78d4731ffc6211d07a0d69c92c559ba792.)

Change-Id: I5d1b41f029c9c49a2d60a066a5fb0ed0f52f4b52