Added application/xml for RSS MIME types

Based on research on the [issue
list](https://github.com/h5bp/html5-boilerplate/issues/989)
Merge pull request #1010 from richardcornish/master

Added `application/xml` for RSS MIME types
Update CSS image replacement technique

The new technique avoids various problems with any text-indent method.
The benefits are:

* No box of any kind is drawn offscreen, so there is no risk of
  related performance problems in old iOS devices.

* No need to specify a text-alignment and hide overflow since the text
  is crushed to take up no space.

* No need to hide `br` or make all fallback HTML `display:inline`
  because unlike the text-indent approaches, this method is not
  affected by those scenarios.

* Fewer styles are needed as a result of these improvements.

The function of the new CSS is as follows:

* `font: 0/0 a` is a shorthand property that reduces the font-size and
  line-height to 0. The `a` value acts as a font-family. The CSS
  validator complains that using `0/0` in the shorthand `font` property
  is not valid, but every browser accepts it.

* `text-shadow: none` makes sure than any inherited text shadow is
  removed, otherwise it will show over the image.

* `color: transparent` is only really needed in browsers than don't
  completely crush the text to the point of being invisible. Safari 4 is
  such a browser (but extremely rare). Leaving it in for now in case
  there are any mobile browsers that require it. Upon further testing,
  it may be possible to remove this declaration.

Some parts of the pre-existing image replacement technique have been
retained. The border and background resets are useful when using IR on
form submit inputs or buttons, as well as when links use default borders
or backgrounds

Close #1005
Cloud Sites (and probably other cloud/shared hosting) needs a RewriteBase set for rewrites to work. See http://www.rackspace.com/knowledge_center/index.php/Why_is_mod_rewrite_not_working_on_my_site
Update .htaccess
Add RewriteBase subdirectory note.
Add 144×144px touch icon for third-generation iPad

See http://mathiasbynens.be/notes/touch-icons. Closes #1020.
Redesigned touch icons and favicon

New icons designed to be sharper on the pixel grid, with slight light
source variations that are pleasing to the eye in a touch environment.
Also put through ImageAlpha and ImageOptim for added optimization.
Please see
http://dl.dropbox.com/u/2066483/h5bp-icons/docs/comparison.png for
before/after comparison.
Merge pull request #1025 from richardcornish/master

Redesigned touch icons and favicon
Further optimize the new touch icons

   apple-touch-icon-114x114-precomposed.png |  Bin 3247 -> 3242 bytes
   apple-touch-icon-144x144-precomposed.png |  Bin 3779 -> 3777 bytes

Ref. #1025.
Updated jQuery to 1.7.2

Signed-off-by: Jonathan Fielding <j.fielding@me.com>
Fixing typo in css class. Fixes #1028
Actually fixing #1028. Thnx @niftylettuce
added a try/catch block to make log work with 'use strict'
Merge pull request #1029 from philipwalton/strict-log

added a try/catch block to make log work with 'use strict'
Merge pull request #1026 from jonathan-fielding/master

Updated the jQuery to 1.7.2
Corrected spacing
Comment-out RewriteBase by default. This allows for "no-configuration" flexible deployment. Some servers need this setting configured, but the value depends on deployment location.
Merge pull request #1036 from alecrust/patch-1

Corrected spacing
Merge pull request #1015 from WraithKenny/patch-1

Add RewriteBase to .htaccess - commented out by default as it allows for use w/o configuration.