This gets rid of the 'sources' directory and allows all sources
of a given Android application to be in the same directory tree
without using a symlink trick.
Note that apps/<name>/Application.mk is still required though.
A later release of the NDK will get rid of it too, but the change
is too drastic for the upcoming release.
The change moves various source files from sources into their
app/<name>/project/jni directory as well.
The whole documentation is updated to reflect the change.
Note that the app will only build against an android-4 SDK.
(Interestingly, the resulting binary runs very well under android-3).
This also adds missing license headers to the 'two-libs' sample.
This is used to reduce the number of distributable prebuilt packages
(i.e. linux-x86_64 is not needed anymore).
Also fix build/tools/build-toolchain.sh to properly copy the GPL and LGPL
license files into the generated prebuilt packages.
Also add a .gitignore files to get less spew from 'git status'
