cleanup and module support (#77)

* cleanup and module support

chown_linux.go

@@ -5,8 +5,8 @@ import (
 	"syscall"
 )
 
-// os_Chown is a var so we can mock it out during tests.
-var os_Chown = os.Chown
+// osChown is a var so we can mock it out during tests.
+var osChown = os.Chown
 
 func chown(name string, info os.FileInfo) error {
 	f, err := os.OpenFile(name, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, info.Mode())
@@ -15,5 +15,5 @@ func chown(name string, info os.FileInfo) error {
 	}
 	f.Close()
 	stat := info.Sys().(*syscall.Stat_t)
-	return os_Chown(name, int(stat.Uid), int(stat.Gid))
+	return osChown(name, int(stat.Uid), int(stat.Gid))
 }