Camel servlet extension

[ppalaga]

Assigning to me ( @ppalaga ).

@lburgazzoli mentioned in the Fuse chat:

it would be maybe nice to have a camel-servlet extension
and have an option to customize path, name and so on trough properties
so no need to edit any xml
I think in general we should try to move as much as possible at build time

another interesting thing would also be to configure [via configuation.properties] the default rest configuration from the camel-servlet extension moved to #2585

Following up #2542