Re-structure packages

Overhaul of package structure and other cleanup.

file/file.go

@@ -0,0 +1,15 @@
+// Package file contains filesystem functions
+package file
+
+import (
+	"os"
+)
+
+// Exists returns true if a file exists
+func Exists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return !info.IsDir()
+}