Changing the directory structure of SCAPI so that it will be more friendly
to the Open source community. This is the first of several commits regarding the dir structure.

changes made:
1) removed the Code/ directory, instead:
- the java code of scapi sits under src/java/
- the jni (c++) source code sits under src/jni/

2) changed the Docs/ dir to doc/ and moved the UML/ dir under doc/

3) removed all external libraries from the repository, instead:
the external libraries are now git submodules that sit under lib/