The internal representation of turn restrictions expects only one
`from` way and only one `to` way.
`no_entry` and `no_exit` turn restrictions can have multiple `from` and
`to` ways respectively. This means they are not fully supported by
OSRM's restriction parser.
We complete support for these turn restriction types by parsing all
ways and converting a valid restriction with multiple `from`/`to` members
into multiple internal restrictions.
Michael Bell
3cfd0e8334