inveniomanage: fixed import of sqlalchemy
invenio.base.globals: fixed current_blueprint
invenio.ext.breadcrumb: created extension

* Automatized processing of breadcrumbs.
* Decorate blueprint functions with register_breadcrumb to display breadcrumb path.
* Set blueprint-wide breadcrumb base with default_breadcrumb_root.

Signed-off-by: Krzysztof Lis <krzysztof.lis@cern.ch>
example usage of invenio.ext.breadcrumb
Merge pull request #19 from Demestotenes/code-structure

Breadcrumbs