Introduce the concept of multiple asset types

the ucomm_asset_request form shortcode can now specify an asset type via the 'type' parameter that allows different assets to be managed across multiple requests for individual users.
For existing requests, use proper meta query

Allows us to show proper screens based on the asset request.
Use the correct capability name for asset access
Add the asset type to the generated post title
Add the Custom CSS plugin temporarily.

At some point, we may remove this from the repository so that it is a regularly deployed plugin in production.
Allow . in a username for WordPress Multisite
Temporarily add ucomm analytics until spine support
Add comment to asset request submission

We'll want to build out additional form elements in the near future.
Merge pull request #4 from washingtonstateuniversity/assets-work

[PR] Introduce the concept of multiple asset types