avocado: Rename test.datadir to test.outputdir and test.depsdir to test.datadir

In fact those names are more clear as to the purpose
of each directory.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
avocado.test: Rename Test.get_deps_path() to Test.get_data_path()

Make the names used consistent between attributes and
methods inside the Test class.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
docs: Update references to Test.get_deps_path to Test.get_data_path

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Merge pull request #114 from lmr/datadir-outputdir

avocado: Rename test.datadir to test.outputdir and test.depsdir to test....