Support different variations of languages in Browser --> Language audience option

[#1]

Currently the Browser --> Language option when creating audiences only supports specific browser languages.​ Targeting "English" language browsers only works when 1) the user's browser language is  set to "English" NOT "English (United Kingdom)", "English (United States)" etc OR

2) "English" is at the top of the list in the user's list of browser languages

This specificity significantly restricts the targeting ability, and it would be nice to have an option to support all the browser languages using the Target UI.

[#2]

+1 from me @surebee

[#3]

+2