[Bashdb-remake] remake 4.2.1 (Patched GNU make 4.2.1 with tracing, profiling, debugging)

[Rocky B. <ro...@gn...>]

And on github. On github the default branch is this version and will be the
latest version.
"master" may be one of these branches. Each release we support, e.g. 3.82,
4.1, 4.2.1, has a branch. Specific points along those branches are tagged
with a release.