Bug 796530 - Add Keyboard for Latin America

From "Open Web Device - Keyboard Recommendations - Release 1" [1]

    "Numeric and symbols keyboards may be different depending on
    the keyboard language."

Most Spanish Latin America countries use "$" as the currency
symbol instead of "€" [2]. To accomplish this a layout for Latin
America was add.

Note: This is also how Android does it.

[1] https://wiki.mozilla.org/images/2/20/Keyboard_Specs.pdf
[2] http://en.wikipedia.org/wiki/Central_banks_and_currencies_of_Central_America_and_South_America