AJAUDIO-51: Fix use of unitialized data by opening the data source
before setting it.

Added implementation of reset, separate from stop, to match the
behavior of existing Android MediaPlayer.

Change-Id: I506a775d4242a586a58198234cf0ed47e277729b
Rework scons files to conform to the other AllJoyn services

- Build both liballjoyn_audio.a and liballjoyn_audio.so on Linux/OpenWrt
- Samples will be linked against liballjoyn_audio.so on Linux/OpenWrt
- ABOUT_BASE has been removed
  - Uses public header files and libraries only
- ALLJOYN_DISTDIR has been added (used when building outside of core AJ source tree)