feat(internal resources) - add the capability to declare some resources as
internal, to be used only for data manipulation.
feat(internal resources) - add more tests.
Improve the documentation.
feat(internal resource) - improve the documentation
Merge branch 'internal-resource' of github.com:amagdas/eve into amagdas-internal-resource
Update docs for Internal Resources

- Move fature docs to features.rst and improve both story and snippet.
- Add 'internal_resource' to config.rst
Explipit is better than explicit.

Like all resource settings, 'internal_resource' has a default setting
too. Also, update docstrings where needed.
docstrings update for future dev-docs
internal_resources and post_internal()
Merge branch 'amagdas-internal-resource' into develop