Cappuccino Cappuccino

Add format parameter index support to sprintf.

This is primarily useful in cases when the format string can vary, but the argument order will not, as is often the case with format strings in Localized.strings files.

From http://perldoc.perl.org/functions/sprintf.html:

An explicit format parameter index, such as 2$. By default sprintf will format the next unused argument in the list, but this allows you to take the arguments out of order.

See also this Cocoa example: http://stackoverflow.com/questions/1063843/is-there-a-way-to-specif...
https://github.com/280north/cappuccino/commit/7be6352531a94c7ac4f9a...