[WIP] Add support for parameters and service calls in route conditions

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | no
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

See http://symfony.com/doc/2.7/book/routing.html#completely-customized-route-matching-with-conditions for reference on route conditions. This feature adds ability to use `parameter()` and `service()` functions in route conditions just like in container configuration.

Although I don't like injecting container in all those places, I'm not aware of better solution. What do you think and/or maybe you have better ideas how to do it?

TODO: fix tests, fix Symfony\Component\Routing\Router compatibility issues - probably it's better to make UrlMatcher unaware of container and instead just use a context array for ExpLang and pass it there (so there's no static coupling from UrlMatcher to Symfony's container)