Some clean ups related to service manager and avatar conversion
Clean caches on module and extension install

Recent addition of caching into preload initialization requires cache rebuild on install as well as update and delete. Ulimately need a more granular way to do this, possibly a hierarchical cache?
Switch to use namespaced (Doctrine based) classes directly to fix warning
Implement assetic in debugbar - first pass
Add assets directory.

This is uses to hold assetic managed assets, such as combinied and compressed css and js files. This directory must be writeable by the php processes and readable to all.
Enable some Assetic asset management

Smarty plugin for an assetic block tag. Accepts a list of assets and filters and creates a single URL for the asset to be use in templates. Also, convert default theme.html to use assets managed through the smarty plugin.

Add several PHP based filters to composer.json to allow basic Assetic processing without requiring external commands.

Adapt debugbar module to use Assetic management for scripts and stylesheets. Assets are now built directly from the vendor library code, and deployed in the web accessible assets directory.