There are two distributions of Proguard in the tree:

* external/proguard, which is used by the platform

* prebuilts/tools/common/proguard, which is used by the tools (and
  distributed to users in the tools/ folder)

These are updated independently since one evolves with the platform,
and the other with the tools.

Even though there is a MODULE_LICENSE_GPL license marker in this
directory, note that the Android SDK has an explicit exemption as
described in the license.html file.

The proguard4.7 directory contains the unzipped contents of the
official Proguard 4.7 zip file, available from
    http://proguard.sourceforge.net/index.html

The .zip file is also included here such that the source code can
easily be used (when debugging) or the distribution rebuilt from
source (if for some reason the above repository should be
unavailable).

The sdk/build/tools.atree script will copy part of the proguard4.7
tree into the tools/ directory. It skips the src/ directory (except
for task.properties) and build/. Therefore, we removed the following
two lines from the README file:
   - src      : the source code
   - build    : various alternative build scripts
such that the copied README reflects the actual contents of the
distributed tree.

In addition, we added a paragraph to state that the distribution was
slightly modified.

In addition, the sdk/build/tools.atree will copy in the license.html
file, which was obtained via
       wget http://proguard.sourceforge.net/license.html
  (and the JavaScript redirect element in the <head> was removed)