* but print an error message for every 10 seconds, incase the user
really forget to provide prediction message

Planning: (1) fixed turn signal bug. Localization: (2) fixed wrong order initilized variables. (#1800)

Planning: added right of way status in planning output. Currently, only set right of way when our car is protected by a green light.

Planning: restructured planning.cc so that our calculation do NOT require the assumption that the first ref line is for lane change line when two or more ref lines are used.

planning: enable prioritize_change_lane and add min change lane length check for short-cut change lane decision.

Planning: re-align time of each trajectory point so that we can use the publishing time as the timestamp for planning module -- In this way, every modules in Apollo has a consistent way in defining 'timestamp' in header.

* Planning: used more accurate vehicle state at current timestamp in planning.

* Planning: fixed broken tests.

* prepare for stitching reference line

will create a struct VehicleState that stores all commonly used vehicle
state info, for better multithreading support

Planning: used inheritence for two different types of reference smoothers. TODO: change the codes in common/frame.cc and reference_line_provider.cc to switch smoothers.

* avoid potential data conflicts.