Merge pull request #60 from mneumann/dragonfly_sigstksz2

Fix SIGSTKSZ for DragonFly

Author: alexcrichton

src/unix/bsd/freebsdlike/dragonfly.rs

@@ -1,5 +1,6 @@
 pub const PTHREAD_STACK_MIN: ::size_t = 1024;
 pub const KERN_PROC_PATHNAME: ::c_int = 9;
+pub const SIGSTKSZ: ::size_t = 8192 /* MINSIGSTKSZ */ + 32768;
 
 extern {
     pub fn __dfly_error() -> *const ::c_int;