getting `make` to work without pthread issues

This should fix issue #1, but just an FYI, I get this warning now:

```bash
$ make

cc -g -Wall   -c -o gant.o gant.c
gant.c: In function ‘chevent’:
gant.c:1125:8: warning: variable ‘newdata’ set but not used [-Wunused-but-set-variable]
cc -g -Wall   -c -o antlib.o antlib.c
g++ -g -Wall gant.o antlib.o -o gant -lpthread -lm
```