Support for multiple camel versions

1)
When creating a project let the user choose which version of Camel the route is to be designed for and save that selection as project configuration. The available choices should depend on what versions of Camel we provide support for.

The following code from model plugin can be used:

List<String> supportedCamelVersions = org.fusesource.ide.camel.model.connectors.ConnectorModelFactory.getSupportedCamelVersions();

2)
This should also automatically switch the palette entries / endpoint options for the selected camel version.

3)
We also need to think about providing a way to let users migrate existing projects to support that camel version selection.

4)
We should also allow upgrades / downgrades of the selected version. Probably best done via a wizard.