run-tests: move killdaemons into Test.run() killdaemons() was the only part of runone() looking at env variables. We move killdaemons() into Test.run() to enable us to fully move env into Test.

run-tests: move replacements and port management into Test replacements and ports are really implementation details of a Test. They have been moved to instance variables.

run-tests: move createhgrc() call into Test.run() createhgrc() is an implementation detail of how tests are run. It makes sense to move it into Test.run(). Note that this will cause the test execution time to include the creation of hgrc. The author does not believe this is a significant change worth worrying about.