Merge pull request #193 from XenoPhex/add-force-posix

Allow forcing posix style flags on Windows
diff --git a/optstyle_other.go b/optstyle_other.go
index 29ca4b6..56dfdae 100644
--- a/optstyle_other.go
+++ b/optstyle_other.go
@@ -1,4 +1,4 @@
-// +build !windows
+// +build !windows forceposix
 
 package flags
 
diff --git a/optstyle_windows.go b/optstyle_windows.go
index a51de9c..f3f28ae 100644
--- a/optstyle_windows.go
+++ b/optstyle_windows.go
@@ -1,3 +1,5 @@
+// +build !forceposix
+
 package flags
 
 import (