training-labs scripts cleanup

By request, I am posting a cosmetic changeset to clean up spelling,
formatting, whitespace, and comments (some visible by script users) in
training-labs. A few variables and function names have been changed
(decapitalization, consistency).

Scope: This changeset does not affect the workings of the code and
therefore does not fix bugs. Bug fixes go into separate patches.

Special notes:
* Scripts/Neutron/Neutron.sh still installs quantum, but the naming
  within said script is now consistent. That can only be temporary,
  a switch to a more recent release should happen soonish.

* I left the numbers for steps in some scripts (Glance.sh); maybe
  the manuals are meant to refer to these numbers!? Of course, they
  will change occasionally (this time, for instance, I changed them
  to match the actual order).

* Scripts that use non-standard functionality should use bash, not sh;
  shebangs fixed

* I didn't touch README.md, training-guides-cluster-scripts.tar: these,
  too, are for a separate changeset

Related-Bug: #1312764
Change-Id: I01005f96b03ef3fbeeaa0b9d9d0e804aaed7af83