Simple cross-platform profiling

I think this is something that would make our lives much easier when trying to find bottlenecks. Works on desktop and Android. Use it as such:

```
BEGIN_PROFILING
some_function()
END_PROFILING("some_function()")
```

It prints how much time `some_function()` took in a nice way. You can put any amount of code between the macros and you can call them multiple times one after the other.