Fixes for when link is both a download and external

Since only one background image can be displayed with CSS, the
padding-left was still present when the file was a download but the
image wouldn't come through because it was also external
(rel="external") so the padding left is not always "0" on rel external
to make sure there is no dead space.

Also added the external icon example to the master list of icons.
Fixed display of button-styled summaries in Grids SCSS.
Added aria-label to menubar to give a title for the element with the application landmark (#924).
Merge pull request #2207 from pjackson28/v3.0

Added aria-label to menubar to give a title for the element with the application landmark (#924)
Added aria-labelled by to slide out tab application landmark element.
Corrected value for aria-labelledby for slide out tab.
Added aria-labelledby to application landmark on share widget.
Added aria-labelledby to application landmark on auto-complete polyfill.
Changed pe. to _pe. and replaced  with _pe.main.
Removed JSHint pe global override from footnotes.js.
[calendar] Fix CSS conflicts with grid classes

Ensure 'goto' link has no padding
Remove margins from fieldset children
Merge pull request #2208 from pjackson28/v3.0

Added aria-labelledby to a few a few plugins and polyfills to properly title the application landmark
Merge pull request #2203 from EricDunsworth/v3.0-grids-button-summary

Fixed display of button-styled summaries in Grids SCSS.
Merge pull request #2201 from berubs/issue1356

[calendar] Ensure 'goto' link has no padding
Merge pull request #2210 from berubs/v3.0

Datepicker: Fix min/max date issue.
Closes gh-2199
Merge pull request #2202 from cfarquharson/v3.0

Icons: Fixes for when link is both a download and external
Moved localstorage example JS to a separate JS file.
Changed aria-label to aria-labelledby for menubar application landmark.
Merge pull request #2216 from pjackson28/v3.0

Moved localstorage example JS to a separate JS file and changed aria-label to aria-labelledby in menubar
Added translation for Calendar to i18n.csv and base.js.