Rename *_ETAS_BOA_2_0 to *_ETAS_BOA_2.

This is in line now with the versioning scheme of BOA and the intention
to keep the v2 API stable across minor release. We already reached v2.2.

Signed-off-by: Tobias Lorenz <tobias.lorenz@etas.com>
Updated gitignore.

.project is an Eclipse project file. As we don't use it and
it's not even in the Sources directory, I've deleted it.

manifest files are created as part of the build and thus
shouldn't be in the repository.

Signed-off-by: Tobias Lorenz <tobias.lorenz@etas.com>