run-tests: move env into Test Environment variables are an implementation detail of how tests are executed. This patch moves environment variable logic into Test and completely hides it from the outside. With this patch, a Test can be executed with two lines: init + run(). Tests are still single-use and take a more arguments to the constructor than likely necessary. These will get addressed in subsequent patches.

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.

run-tests: move createenv() into Test createenv() is consulting lots of test-specific variables. It makes sense to attach it to the Test class.

run-tests: move replacements generation into Test The API is a bit funky. Things will look better once all state is captured in Test.