Fix `:pending` metadata to always work.

It got processed immediately by `it`, which means that
if it got set later (e.g. via `define_derived_metadata`)
it would not take effect.
Merge pull request #1739 from rspec/pending-bug

Fix `:pending` metadata to always work.
Keep comment line length to 80
Fix grammer

- End sentence with period
- Start sentence with upper case letter
- Remove extra spacing
Reduce line length to 130
Merge pull request #1740 from yous/patch-line-length

Reduce line length