Concept of an application which components run within

[oliyh]

The most important change here is that system maps can have a :name. Settings for the application are fetched and merged into the settings for each component so that they are available throughout the application.

Furthermore application settings are "deep merged" with the other settings resulting in the ability to override component level settings at an application level.

Other bits include improving some tests, removing the zk client in favour of the curator client and changing the file config supplier so that it can look for multiple files.

[jonpither]

Could you squash the commits into 1 please, or split the PR...

[oliyh]

Squashed to a sensible level