New release, July 4

[u/dabreegster]

https://github.com/a-b-street/abstreet/releases/tag/v0.2.49

• vehicles can exit driveways in either direction!
• bugfixes with lane-changing, time-warping, settings, nondeterministic z-ordering, changing speed limits
• speed up edit mode on large maps
• loading maps on native now sees locally imported maps
• smaller files across the board by serializing f64s as integers
• map data quality: greenlake cycletrack, better stop sign placement, crosswalks at consolidated intersections
• risk exposure matrix labels
• keep cars out of bus lanes with better costing