enforce indent-tabs-mode
fix indentation
follow header conventions
stripe-buffer-mode: use cond instead of if+progn
make compatible with hl-line

Advice `hl-line-highlight' like it is done in `hl-line+.el', but only
if that isn't available (so that the same advice isn't applied twice).

There is no other reason why stripe-buffer would need hl-line+, and
now there is none.
fix several issues in stripe-listify-buffer

- `featurep' only returns non-nil if the feature is *loaded*, not when
  it isn't loaded but can be found on the `load-path'.  So this makes
  no sense: (if (featurep f) (require f) ...)

- Now that `hl-line' is enough we don't have to check for `hl-line+'
  anymore and can just always enable `hl-line-mode'.

- Setting `cursor-type' to nil is evil.  In some modes it might make
  sense, but until there is a way it should be nil we should not touch
  it at all.

Update Commentary accordingly.
link to original and correct authorship information
eliminate second return point so we don't need cl
stripe-max-buffer-size: improve doc-string
make stripe-listify-buffer interactive