Objective-C and Swift binding available for GMP

[Otto van Verseveld]

Recently I added on https://github.com/githotto/osxgmp my first GitHub
project with which developers can use Apple's Xcode, Objective-C | Swift
language in order to explore GMP features.
Although this project is not a real contribution to GMP, I'ld love to see
both language bindings (which were missing) being added to the current list.

Since this is a work in progress, currently most Integer (i.e. GMP chapter
5 functions) arithmetic is available, but in future versions I'ld like to
add more of the great functions hidden in GMP!

Any comments or suggestions are very much appreciated, thanks in advance!