proguard: fix release build

Prevents obfuscation of some symbols
to fix release builds by adding a custom proguard
configuration, based on Android optimised defaults.

* protect AIDL and SWIG symbols
* protect support library (uses reflexion)
* protect OrmLite (uses reflexion)

Tuleap: #128
Change-Id: Ie1fe8fa6af1a6968ca0889f8fe343e58a35071b6