Downloads occasionally fail at RAM Checksum step

[PropGit]

Downloads are now frequently failing at the RAM Checksum step. It's not clear if this is due to a change in BP Launcher code or not.

[PropGit]

This was discovered to be due to, apparently, changes in the serial behavior of Chrome v0.77?+ (starting version unknown) where Chrome occasionally pauses serial transmission for a few milliseconds (in tests) and then resumes. Presumably this is to perform some other critical task, but it causes the Propeller Micro Boot Loader to mistakenly treat the packet as finished and move on to the next (which appears to it to be the next part that is resumed-transmitted by Chrome).

This is temporarily fixed in v0.11.6 and later officially in v1.0.1, PR #110 and #112

At a future time, need to resolve this in a better fashion. See Issue #109