ios build wrapper for serval-dna

I've create a build script that produces a fat static library for use in iOS projects. Basically the script runs configure and make for each of the 5 architectures. In a perfect world the xcode project would build the c source directly so you could debug inside of serval but I ran into too many problems with that approach.

There's an example ios app that uses this work here

https://github.com/foozmeat/ServalDNAExample

Please let me know if you have any questions.