Fix `SymLinksIfOwnerMatch` typo in .htaccess

Ref. gh-1209
Add a `CONTRIBUTING.md` file

Move the information on contributing from the bundled documentation to a
new root file - CONTRIBUTING. This is both a more meaningful location
(not part of code documentation) and allows us to take advantage of
GitHub's latest UI changes that prompt people to read a repo's
guidelines before reporting issues or opening pull requests.
Enforce coding style in main.css print styles
Remove duplicate `markTimeline` from plugins.js

Fix gh-1211
Disambiguate chromeframe prompt wording.
Updated jQuery to 1.8.2

jQuery 1.8.2 has just been released. Google's CDN has not yet
been updated, but it shouldn't take too long before it is.
Merge pull request #1219 from ryanve/master

Disambiguate chromeframe prompt wording.
Improve `console` method stubbing

Avoid browsers with `console` and `console.log` throwing errors for some
of the other methods that they did not support.

Fix gh-1206
Close gh-1218
Update CHANGELOG
Fix `console` stubbing method in oldIE

Expose `console` object to global scope in IE6 and IE7

Reference: gh-1229
Further improvements to `console` stubbing method

These improvements are:

- cache current method in `while`-loop to reduce property look-ups
- use `if` as the conditional assignment in `while`-loop in order to improve performance and readability

Reference: commit 578f377
Closes gh-1229
Update CHANGELOG
v4.0.1
Fix missing parenthesis to CHANGELOG.md
htaccess: sort the values of directives alphabetically
htaccess: for consistency, use `mod_php5.c`
Remove broken link to PDF in cross-domain docs

Adobe have changed the location of the PDF. There is no gaurantee that
it will remain at the new location either. Since we already link to an
Adobe article about the cross-domain policy spec (that links to a PDF)
we don't need to link to both.
Updated 'jQuery' to 1.8.3.
Merge pull request #1253 from bmcustodio/jquery-1.8.3

Updated 'jQuery' to 1.8.3.
Add note about `AddOutputFilterByType` in Apache < v2.3.7