Simplify the bus_index code

Instead of comparing the paths components by components just compare the
complete strings. The behavior of this change should be backwards compatible
with the old code.
Do not call humanize on role names

We should really not have "Nova-multi-controller", but
"nova-multi-controller": if people then try to use the capitalized name
with knife, it'll just fail.
Merge pull request #562 from rhafer/pull-req-release-pebbles-master-baca0ec1ac0c56c4847b1c18747abd04377f6bd8

https://github.com/crowbar/barclamp-crowbar/pull/562

Merged by devtool for cloudsleuth
Merge pull request #622 from vuntz/fix-cases

Do not call humanize on role names