mesa: retry twice instead of 9 times

The 408 pre-release has encountered all kinds of problems and a constant among
them has been that mesa sending 10 packets every two minutes on broken flows
behaves significantly worse than old ames sending just one.

There have been multiple mitigations for "stuck" flows recently but having any
that exist be 10x worse than before is unacceptable.

Release vere-v4.5 (#1041)

Release vere-v4.4 (#1035)

Revert "term: clamp zero window size from Docker PTY (#959)"

This reverts commit 4e2a283, reversing
changes made to de22bf0.

unix: parametrize freeing functions

Release vere-v4.1 (#947)

Release vere-v4.0 (#915)

renames `c3_n` to `c3_w`, including variables and `note` functions

Release vere-v3.5 (#862)

Release vere-v3.4 (#822)