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`
Update CHANGELOG
Update normalize.css to v1.1.3
Use one apple-touch-icon instead of six

This commit removes five Apple Touch Icons with different sizes for
the same icon and adds a new icon `apple-touch-icon-precomposed.png`
with a resolution of 152×152px.
Apart from that it adds documentation on how to add more icons if
you need them within your project.
Using only one Apple Touch Icon saves time and is enough in most
cases.

Closes #1367.
Closes #1425.
Add version & license info in .htaccess / main.css

Make it easier for people to know what version of the `.htaccess`
and `main.css` files they are using and under what license these
are provided, by adding this information within the files.

This is useful primarily when developers only copy these files from
the HTML5 Boilerplate project, forget to update their project's change
log or simply do not use anything similar to a change log.

Fix h5bp/html5-boilerplate#1424.
Update CHANGELOG

Include all changes that are not yet mentioned in the `CHANGELOG.md`.
https://github.com/h5bp/html5-boilerplate/compare/0adda79fee6ddccc46d0ba427c7e3d7277f39230...d1443410031e06421b70cd2fe39fc784c555e60a
v4.3.0
Remove notes about Google Chrome Frame from docs

Currently we don't use Google Chrome Frame anymore as support for
it will end at the end of the year.
This commit removes references to Chrome Frame within the
documentation. It is related to 2cf1ef7.

Reference #1433.
Remove IE conditional classes

The reasons behind this decision include the following:

* This project will drop legacy browser support (see #1050), therefore,
  the use for conditional classes for IE 8+, becomes much more limited.
* IE 10+ does not support conditional comments:
  http://msdn.microsoft.com/en-us/library/ms537512%28v=VS.85%29.aspx.
* Users do and can develop easily without using the conditional
  classes, this technique being very limited in scope as no other
  browser versions are explicitly target in the same way.
* It fixes the issue that prevents IE from honouring
  `<meta http-equiv="X-UA-Compatible" content="IE=edge">` (see: #1187).

This change also removes the related documentation.

Close #1290 and #1187.
Update to normalize.css v2.1.3

Ref: #1050.
Remove IE 6/7 hacks from `main.css`

Ref: #1050.
Show `outdated browser` prompt to IE 6 and 7 users

Ref: #1050.