Exchange support in the Email application can be removed.  In order to do so,
run the remove-exchange-support.sh script and rebuild the application.  In case
the script doesn't work, here's how to do it manually.

1. Remove everything under src/com/android/exchange/ and
   tests/src/com/android/exchange/.
2. Check all the *.xml and *.java files, and remove all the lines surrounded by
   EXCHANGE-REMOVE-SECTION-START and EXCHANGE-REMOVE-SECTION-END.
3. Check all the *.java files and remove all imports from com.android.exchange
   and its subpackages.