Compile errors on Mac OS

[dctucker]

Source/Sim/CustomColonyCreator.cpp:75:32: error: use of undeclared identifier 'TextColour'

I think this is because the compiler isn't defining unix. Adding || defined(__APPLE__) to the tops of Unix.h and Unix.cpp should resolve this error.

Source/Sim/ColonyStatistics.cpp:51:28: error: implicit instantiation of undefined template 'std::__1::basic_ostringstream<char, std::__1::char_traits<char>, std::__1::allocator<char> >'

This can be resolved by putting #include <sstream> to the top of ColonyStatistics.cpp.

[Spartan322]

In truth a sane check with unix's isatty function would be the best solution alongside a more general unix check, given not every unix system (including certain versions of OSX [or whatever its called now]) supports the color ansi escape colors, and they aren't usually ignored, but that's also yet to have been done.