_slot_operator_update_probe: fix bug #508762

This fixes the check_reverse_dependencies function (inside the depgraph
_slot_operator_update_probe method) to account for irrelevant parent
atoms from parents that need to be rebuilt or have been involved in
unsolved slot conflicts.

X-Gentoo-Bug: 508762
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=508762
Reviewed-by: Brian Dolbec <dolsen@gentoo.org>
QA: Add a set of checks for bash-completion files

Add checks for common mistakes when installing bash completion files:
legacy directory, incorrect naming, missing aliases, deprecated 'have'
function.

Acked-by: Brian Dolbec <dolsen@gentoo.org>
repoman: Do not check for indirect inherits of deprecated eclasses

Complain only about deprecated eclasses that are inherited directly.
Checking indirectly inherited eclasses is pointless since the ebuild
maintainer can't really do anything about it --- it is up to
the maintainer of one of the directly inherited eclasses.