Fixes to support distributed scenario

Added parameter for TestController to allow agents to connect to remote host
-Using CmdLine package to simplify argument parsing #17 

Catching exceptions from Json serializer that caused agent to crash when worker trace messages are written to standard output

Using thread-safe collection for worker connections

Force copy of Microsoft.Web.Infrastructure.dll to run TestController app on full IIS - Not GAC'd
@abnanda1 @davidfowl 
This try/catch is not strictly necessary since the agent isn't writing any trace information to the worker.
We could send the exception information back to the agent as a log entry as a catch all for a failed agent to worker command.