Return caching to AppCatalog

Cache Application logo and dynamic_ui markup on local file-system
using `cache.with_cache` decorator. Objects are cached using cPickle
module to allow the function cached by `cache.with_cache` to return
arbitrary objects, not only string or buffer.

Change-Id: Ia0d89b38be1f0776d6e910e3126d89c978db0f10
Implements: blueprint ui-local-cache
Partial-Bug: #1312251
Merge "Return caching to AppCatalog"