[ally.maintain.tabFocus] Safari doesn't include links in tab sequence by default

[rodneyrehm]

Concerning: ally.maintain.tabFocus
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/601.7.7 (KHTML, like Gecko) Version/9.1.2 Safari/601.7.7
ally.js version: 1.1.1

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Safari's default behavior of the Tab key is to skip links (<a>). To include links when cycling through the document's tab navigation order, one must press Option Tab (Option is also known as Alt and depicted by ⌥).

This behavior can be configured in Preferences > Advanced, where the option Press Tab to highlight each item on a webpage toggles the inclusion of links (<a>). If disabled, Option Tab will cycle through all elements, while Tab will cycle through everything but links. If enabled, Option Tab will select everything but links and Tab behaves like any other browser would.

Currently ally.maintain.tabFocus will not react to Option Tab because the we're missing ?alt.

This is also the reason capabilities.shiftFocusOnTabToLink was introduced to tests. We should ask @browserstack if this Safari configuration can be provided in the capabilities somehow?