Demos: Updated page sections info on intro page

Fixes gh-7052
Build: Updated AUTHORS.txt
Textinput: Correct padding-right for input with clear button

Fixes gh-7011
Closes gh-7072
Icons: Same size for all icons and center the image

Fixes gh-6356
Closes gh-7031
Icons: Alphabetise icon examples in the demos
Icons: Fixed markup and style guide issues on grunticon demo page
Button: Correction of wrong border-radius property

Fixes gh-7073
Closes gh-7074
Toolbar: Corrections in back button info on demo page

Fixes gh-6835
Closes gh-7075
Collapsible: modify typo in _setOption

Fixes gh-7054
Collapsible: Correctly inherit options from set and fix iconpos handling

Fixes gh-7044
Fixes gh-7062
Textarea: Use feature detection to avoid setting height to 0 on IE8

Also replaces the immediate height update with a timed one, because the
immediate height update issued from _autogrow() is having no effect in IE.

Fixes gh-6998
Textarea: Save and restore scrollTop during autogrow height update

Thanks go to Kangsik Kim <allsteady@gmail.com> for the idea to set scrollTop

Fixes gh-6898
Popup: Remove arrow background div

Fixes gh-7037
Popup: Turn off clickable area focus outline
Textarea: Turn off overflow for autogrow textarea widgets

This has two benefits:
1. Scrollbars will not affect the reported initial height
2. The scrollbar will not be displayed during the initial animation, only to
   disappear during the final animation frame

Fixes gh-6996
Navigation: Add navigation hash processing demo

Pass hash query params into location via page's data-url
Illustrate history retention via allowSamePageTransition
Custom select: Transfer value of "overlayTheme" option to dialog

Since 2451b0b99ad8d02e1367827741323d40f870ad91 both the "overlayTheme" option
and the "theme" option are transferred to the dialog's data-theme attribute,
resulting in two copies of the data-theme attribute being set on the dialog div.

If the "overlayTheme" option is not specified, the "theme" option is fanned out
to both the dialog's "theme" option as well as its "overlayTheme" option.

Fixes gh-6975
Flipswitch: Transfer tabindex to "on" button and make input unfocusable

The "on" button must be an anchor for it to be focusable just like an input even
when it does not have an explicitly set tabindex. Although the input becomes
unfocusable, a focus handler that transfers focus to the "on" button is
nevertheless attached to it in case third-party code focuses the input manually.

Fixes gh-6955
Panel: Ignore click event whose default has been prevented

Check whether the default on the event that would close the panel has been
prevented, and ignore it if so.

Fixes gh-6693
Build: copy jquery.js from the external/jquery directory

Fixes gh-7032