Create needs to support inputting a command line

[jaredpar]

The majority of builds for C# use msbuild but there are still plenty of places that use other build systems that don't produce binlog files. So long as it's possible to extract the csc command line out of those builds, it is possible to create compiler logs. Need to allow for an option to just specify the command line directly.

[jaredpar]

PR #321 explored what this would look like in the tool. One of the findings is that for RSP files it requires both the file and the context path from which to evaluate the file as many items in the file are relative.

Getting to the end of the PR I just didn't like where it was going. The extra path felt wrong and it didn't connect for me in the scenario. Also there isn't any real demand for this right now which makes it hard to validate this was going in the right direction.. Closing until there is a more concrete scenario that is driving the request.