Add documentation for iOS web applications

Add several options to improve iOS web apps with meta tags when
adding a web page to the Home Screen.

Closes #1352.
Update to Normalize.css 1.1.2
Update to jQuery 1.10.0
Update to jQuery 1.10.1
Update to Google Universal Analytics

This is an optimized version of the official Google Universal Analytics snippet,
based on http://mathiasbynens.be/notes/async-analytics-snippet.
The only difference is that this version still uses
`document.getElementsByTagName('script')[0]` instead of `document.scripts[0]`
for Firefox < 9 support.

Unminified, optimized code:

    (function(window, document, script, variableName, scriptElement, firstScript) {
      window['GoogleAnalyticsObject'] = variableName;
      window[variableName] || (window[variableName] = function() {
        (window[variableName].q = window[variableName].q || []).push(arguments)
      });
      window[variableName].l = +new Date;
      scriptElement = document.createElement(script);
      firstScript = document.getElementsByTagName(script)[0];
      scriptElement.src = '//www.google-analytics.com/analytics.js';
      firstScript.parentNode.insertBefore(scriptElement, firstScript)
    }(window, document, 'script', 'ga'));

    ga('create', 'UA-XXXX-Y');
    ga('send', 'pageview');

Minified:

    (function(b,o,i,l,e,r){b.GoogleAnalyticsObject=l;b[l]||(b[l]=function(){(b[l].q=b[l].q||[]).push(arguments)});b[l].l=+new Date;e=o.createElement(i);r=o.getElementsByTagName(i)[0];e.src='//www.google-analytics.com/analytics.js';r.parentNode.insertBefore(e,r)}(window,document,'script','ga'));ga('create','UA-XXXX-Y');ga('send','pageview');

Closes #1347 and #1369.
Docs: update information about `print styles`

Fix: h5bp/html5-boilerplate#1386
Remove Google Frame message

As said at http://blog.chromium.org/2013/06/retiring-chrome-frame.html Google Frame was retired/obsolete.

Changed "chromeframe" class to "browsehappy"
Add vertical centering for audio-, canvas- and video-tags

Remove the gap between videos, audio and canvas and the bottom of
their containers by vertically centering the tags.

Closes #1326.
Remove Chrome Frame meta tag and HTTP header hints

See also `Retiring Chrome Frame - developer FAQ`:
https://developers.google.com/chrome/chrome-frame/

Close #1396.
Add `initial-scale=1` to meta viewport

iOS 6 fixes the infamous orientation change bug, so a better experience
is provided by reintroducing `initial-scale=1`.
Updating jQuery to 1.10.2.
Further optimize the apple touch icons

Reduce the total size of the icons by 1.7KB using ImageAlpha
(16 colors - no visible difference) and ImageOptim.

Close #1406.
Update CONTRIBUTING.md

* Reflect the recent changes in @necolas's Issue Guidelines:
  https://github.com/necolas/issue-guidelines.
* Add note about not opening issues and pull requests regarding the code
  in the Apache Server Configs, jQuery, Modernizr and Normalize.css.
Update to Apache Server Configs v1.1.0
Docs: Update `.htaccess` related info and links
Docs: Update section about the X-UA-Compatible meta option

Chrome Frame is not supported anymore and we removed the option in
8fc2650.
This commit removes the documentation about Chrome Frame in the
X-UA-Compatible meta tag docs.

Related to #1396.
Further optimize the apple touch icons

Reduce the total size of the icons by 172 bytes using zopfli.

Close #1415.
Docs: Update the `Track JS errors in GA` section

Add column number parameter to the example to reflect the recent changes
in the specification and in the Chrome and IE 10 implementations.

http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#errorevent
https://code.google.com/p/chromium/issues/detail?id=264197

Close #1417.
Compress .png files losslessly

Use `zopfli-png` with 1000 iterations, `pngout /r` with various block sizes and deflopt.

apple-touch-icon-114x114-precomposed.png | Bin 865 -> 751 bytes
apple-touch-icon-144x144-precomposed.png | Bin 947 -> 939 bytes
apple-touch-icon-57x57-precomposed.png   | Bin 495 -> 450 bytes
apple-touch-icon-72x72-precomposed.png   | Bin 575 -> 512 bytes
apple-touch-icon-precomposed.png         | Bin 495 -> 450 bytes
apple-touch-icon.png                     | Bin 495 -> 450 bytes

The total difference is -320 bytes.

Closes #1418.
Move font-related base declarations to `html`