Unpack whole response from the RTI service
Set title from the provider.provides dict
Updated providers to follow new syntax
Updated tests
Removed out-of-date documentation
Added `title` attr to the docs
get_provider raises appropriate Exceptions

- MultipleProvidersFound
- NoSuitableProviderFound
TransportService no longer raises Exceptions
Give appropriate user errors and logging
Updated providers for handling RTI

Now providers say if they support a particular RTI type or not.
Updated tests for the new provider exceptions
Added base ProviderException
Places representations catch all ProviderExceptions

This way we don't give RTI links if we have Multiple or No RTI for that
particular POI.
Added test to catch multiple RTI providers in POI representation
Updated the docstring for get_provider
Added more information to RTI documentation
mesages -> mesSages, corrected JSON style
Merge pull request #26 from ox-it/rti-links-titles

RTI link titles