Unwanted Lines being rendered in various sims.

[Denz1994]

These thin hairlines are being rendered across several sims. So far they have been found in Pendulum Lab , John-Travoltage #193, CCK #408, and Masses and Springs #278.

There doesn't seem to be a consistent means of reproducing this bug. Perhaps, this has to do with how certain browers are painting the scenes. Current workarounds include wrapping nodes in a slightly larger rectangles so the whole node gets painted, before the next step call. There are possibly better solutions to this.

This isn't sim breaking and will require some time for investigation. Tagging @ariel-phet to assign priority and steps moving forward.

[ariel-phet]

Given the minor nature of this bug marking deferred.

@lmulhall-phet please be aware to note in this issue future places where this bug is seen

[phet-steele]

Another in Wave Interference 1.0.0-rc.1:

macOS 10.13.6 Chrome.

[KatieWoe]

Something similar seen in phetsims/qa#280 on Mac 10.11.6 on chrome. Recorded with showPointerAreas, since red is easier to see, but occurs without.
https://drive.google.com/file/d/1kVoBpPh09Sk8Khyx4R3xpKyRdmvw_AEH/view?usp=sharing

[KatieWoe]

Appearing in Mac 10.14.3 firefox on first screen of phetsims/qa#228 when dragging the box to the left when it is 100x100. Only seem to see when using a string test.

[liammulh]

Un-assigning myself since I no longer work on QA.