Config server with settings

Added setting interface (ServerSettings and ServerInternalSettings) for server to access its configuration properties.

Enabled to obtain a server property with Config.get + property settings. Replaced the previous Apache Configuration + constant string property-accessing-pattern. 
If _code formatter_ settings are updated, could you guys update these files here too? https://github.com/neo4j/neo4j.github.com/tree/master/code-style (They're linked in the [Contributing Code](http://neo4j.com/docs/2.1.5/community-contributing-code.html#community-contributing-code-commit-messages) docs).