Fixed gems 1’s compilation errors with newer cc

[andyli]

I fixed some compilation errors for gems 1, such that it can be compiled on Mac/Linux using:

• Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
• cc (Ubuntu/Linaro 4.7.3-1ubuntu1) 4.7.3

My changes:

• Added function declarations.
• Added void return type.
• #include <malloc.h> => #include <stdlib.h>

PS.Since I don't know how to install the Utah Raster Toolkit on Mac/Linux, I haven't tested the AALines example.

[erich666]

Thanks! These look straightforward. I'll take a careful look over the holiday break and then pull.