Add a non-breaking space to _s_post_nav().

Sometimes the title length of a previous or next post would cause
the arrow (larr/rarr) in the link to be wrapped to the next line.
Adding a non-breaking space between the title and the arrow will stick
it to the last word in the title.
_s: Simplify entry meta output

- Add entry-footer consistency between content-*.php files
- Move in a function _s_entry_meta() to avoid duplicate
Update README to be more consistent

Wrap all file paths in '`', capitalize properly, fix grammar.
Merge pull request #532 from Automattic/Entry-Meta-Consistency

Make entry meta more consistent throughout _s and gut out code duplication.
Merge pull request #533 from lchski/lchski-readme-consistency-fixes

Update README for consistency.
Revert "_s: Simplify entry meta output"
Merge pull request #536 from Automattic/revert-532-Entry-Meta-Consistency

Revert "_s: Simplify entry meta output"
Merge pull request #527 from kovshenin/master

Add a non-breaking space to _s_post_nav().
_s: Simplify entry meta output

- Fix entry-footer inconsistency between content-*.php files
- Move in a function <code>_s_entry_meta()</code> to avoid duplication

---

At the moment there is an inconsistency between content.php and
content-single.php regarding the .entry-footer output.

In my opinion content.php output is would be better to use because it's
easier to translate and allow more customisation.

Finally by moving it into <code>inc/template-tags.php</code> we are
getting rid of some duplicated code.
Revert "_s: Simplify entry meta output"

This reverts commit 9e6640193006f0af8ef6acca4f4ee0901b636bd2.