Expose Midgard configuration through midgard_key_config to PHP

[bergie]

With Trac ticket 1341 it would be very useful if Midgard configuration file used for the request could be used to manipulate parts of Midgard MVC configuration.

It is important to not to expose confidential information like database account, but still provide parts of the config to PHP apps.

[indeyets]

related functionality was implemented in core for 10.05.1. connection has "config" property now

we need to verify if that was enough or more should be done

[bergie]

This is well enough.