Handle errors when writing to the list of Reporters

We will try to write to a reporter the number of times the ReportManager is
configured to do so.
If no more reporters are available an exception will be raised and the test
will stop running (XXX this needs to be tested properly)
Refactor NetTestLoader and add checkOptions, and add Tor support
Add missing import os
Move the instancing of the t.i.w.Agent into createReport

Add XXX about possible cleaner solutions to the problem
Fix regexp for validating collector address
Add the input of the Measurement to the ReportEntries
Use proper name for AllReportersFailed
Initialize reporters in startNetTest, not Director __init__
Add test deck support to runWithDirector
Add report.close to nettest.done deferred
Fix typo in doneReport docstring
Add failedOpeningReport to reporter created errback
Set testName from class
Shutdown reactor after running all tests, and remove unused code.
write failure instances to report
Open report in director, not generateMeasurements
Clean up NetTest tests
Update MockReporter

the created deferred should not get called until after createReport
is fired
Clean up Director tests
Remove dependency of NetTest on Director and Reporter