Portability part 1 - C99 printf

printf, sprintf, fprintf etc are now all C99 compliant. All except sprintf, which is now signaled as deprecated. This raises a few warnings about sprintf usage in the build. Some I fix with pull requests that will follow. Some others should be fixed by the respective authors.
I agree with your premise, there is no real advantage to using ``sprintf`` and it is inherently more dangerous. However, it is used *a lot* in our code. I think a cleanup job should come first, otherwise we are going to have so many warnings that real problems will go unnoticed in the flow.