Fixed compile warnings with clang

First of all, I'm not suggesting this change should be merged. Quite the opposite actually, but this is probably the easiest way to annotate some code.


I tried compiling the source with llvm-clang. This C-compiler generates a lot more warnings that GCC with the default settings (although gcc-4.8 appears to be catching up). This generated a number of warnings about not fully compatible types in assignments and compares, this patch was the simplest way to silence them.

Most times these warnings reveal that an incorrect data type has been used, which may lead to weird bugs, especially when mixing signed and unsigned data types. The best fix is probably to change the data types of some variables. I don't think I know enough of the freeradius code to do those things.