Add traffic lights and stop lines

[daohu527]

Add traffic lights and stop lines to the map

[stanhua123]

Hi, I wonder when will traffic lights and stop lines be added to the map,thanks a lot

[daohu527]

@stanhua123 It might take me a while since I haven't figured out how to parse opendrive's traffic lights. Maybe this month or later, ideas or code are welcome

[daohu527]

add signal in https://github.com/daohu527/imap/commit/89426df02c92d39a913891530e3f564ac1cab139.

But it still needs to be completed:

1. signal position\type