Evaluate directions 'options' object on backend

[nilsnolde]

The options object should be evaluated server-side. Now, it simply fails silently, when a parameter is specified in the wrong way, i.e. maximumspeed instead of maximum_speed, and returns the route without an error.

@MichaelsJP if and when you have the ressources. Or coordinate with @Elli96 if that makes sense. No urgency here though. But let's keep it in mind for 4.6 the latest.

[rabidllama]

I am moving this to 4.7 as we will have more resources available in the next couple of months

[TimMcCauley]

Related to #233 - will be done then.

[rabidllama]

Lets put this on hold then until v5

[rabidllama]

So in the newer API which will be released in 5.0, mismatched values/parameters should always return an error