Update .gitignore to exclude sublime project files
Remove the subtitle <p> element in trafficsim.html
Add semantic versioning announcement in README.md
Remove pubspec.lock
Implements BacktraceReversibleDBLQ

Employs this class for manulplating lanes and vehicles,
which are reversible (iterating from the last)
and backtraceable (containing an entry pointing to the DBLQEntry
which it belongs to).

p.s. DBLQ = DoubleLinkedQueue
Enhance the doc comments of ReversibleDBLQ
Remove unused numForwardLane and numBackwardLane in Road
Fix a bug in forEachEntryFromLast method of ReversibleDBLQ class
Make the lanes stored in an innerlane first order

I hope the forEachFromLast() method that I impelemented will not be
slower significantly than the forEach() method inherited from the
Iterable class.
Update doc comments for drawLane in Lane
Joint is now drawn only by World

Make Joint becomes an abstract class.
Add drawLabel() to Joint.
SourceJoint can now blink! (updateBlink()).
Rewrite some interface between Joint, RoadEnd, and Road

Now RoadEnd always keeps a copy of outwardLane and inwardLane.
Huge update, I don't know how to say

Main update: Vehicle can now drive to another random adjacent lane when
reaching the road end.

Driver AI coming soooooon!
Corrects typo
The animation is now so smooooooooooooth!!!

I finally know how to use renderInterpolationFactor!
God damn cooooool!
Fixes a bug which wrongly initializes the Camera size
Just change the location of the roads in the world
Renames: lib/src/data-structure.dart -> lib/src/data_structure.dart
Fixes a null object bug in lane.dart
SourceJoint has a dispatch limit and will stop glowing when limit is reached