This commit makes it so that BUILD_COMPONENT holds only the component,
and a new property BUILD_COMPONENT_ALIASES hold the full name of the
component.
This also removes erroneous check for duplicate components, as this can
never happen:
(1) if two components have the same name but different prefixes,
the internal names are still unique between them
(2)if two components happen to have the same name and same prefix, the
latter would override the former
826568a120