Add showimp to commands.

cmd/showimp/README.md

@@ -0,0 +1,21 @@
+# showimp
+## show imports
+
+This will run over a source tree and print any imports that are not in
+the standard library or inside the project.
+
+```
+kyle@nocturne:~/src/github.com/kisom/cryptutils$ showimp 
+External imports:
+        code.google.com/p/go.crypto/bcrypt
+        code.google.com/p/go.crypto/nacl/box
+        code.google.com/p/go.crypto/nacl/secretbox
+        code.google.com/p/go.crypto/scrypt
+        code.google.com/p/rsc/qr
+        github.com/agl/ed25519
+        github.com/conformal/yubikey
+        github.com/gokyle/readpass
+        github.com/gokyle/twofactor
+        github.com/gorilla/mux
+```
+