De-couple the PowerApiValveServerControl class from the CommandLineArguments class.
Convert the local serverInstance variable into an instance field, so that we can explicitly tell it to stop later.
Add the ReposeInProcessValveLauncher class.
Allow for null values to resolve to false.
Implement ReposeLauncher.
Convert ReposeLauncher from an interface to an abstract class.
Consolidate duplicated code: move waitForNon500FromUrl from the derived classes to ReposeLauncher.
Replace calls to waitUntilReadyToServiceRequests with calls to waitForNon500FromUrl.
Extract the waitForResponseCodeFromUrl and waitForDesiredResponseCodeFromUrl methods.
Replace calls to TestUtils.waitUntilReadyToServiceRequests with waitForNon500FromUrl.
Remove the unused waitUntilReadyToServiceRequests method.
Merge pull request #899 from izrik/in-proc-valve-launcher-2

Valve In-process Launcher for functional tests