Use wp_specialchars_decode() in the upgrade debugging email subject, same as the production email.

props markoheijnen.
fixes #26471.


git-svn-id: https://develop.svn.wordpress.org/trunk@26762 602fd350-edb4-49c9-b593-d223f7449a82
Copy edits to the About page:

- Open Sans is Open Source, so it can't meet Open Source
- 'icons and graphics' is redundant
- Let's not overuse 'beautiful'
- Choose > pick so we don't use 'choose' twice in the same line

See #26387.



git-svn-id: https://develop.svn.wordpress.org/trunk@26763 602fd350-edb4-49c9-b593-d223f7449a82