Highlight uncommitted changes in version

If there are uncommitted changes in the app repository when building,
then append `_uncommitted_<random>` to it to distinguish the image
from one built from a clean checkout.

Also change the version used when renaming a container on redeploy to
distinguish and explain the version suffixes.

test/cli/app_test.rb

@@ -32,7 +32,7 @@ class CliAppTest < CliTestCase
 
     run_command("boot").tap do |output|
       assert_match /Renaming container .* to .* as already deployed on 1.1.1.1/, output # Rename
-      assert_match /docker rename .* .*/, output
+      assert_match /docker rename app-web-latest app-web-latest_replaced_[0-9a-f]{16}/, output
       assert_match "docker run --detach --restart unless-stopped", output
       assert_match "docker container ls --all --filter name=^app-web-123$ --quiet | xargs docker stop", output
     end