Merge pull request #29 from dcci/freebsd

First steps to make xctest working on FreeBSD.

Author: parkera

XCTest/XCTestMain.swift

@@ -12,7 +12,7 @@
 //  for running tests and some infrastructure for running them.
 //
 
-#if os(Linux)
+#if os(Linux) || os(FreeBSD)
 import Glibc
 #else
 import Darwin

XCTest/XCTimeUtilities.swift

@@ -11,7 +11,7 @@
 //  Some simple functions for working with "time intervals".
 //
 
-#if os(Linux)
+#if os(Linux) || os(FreeBSD)
     import Glibc
 #else
     import Darwin