Normalize how command is parsed across platforms

In order to pave the way for #28 (closed), the command needs to run the same way across platforms. In order to leverage the functionality of spawn in Node.js, Collector parses the command into arguments itself. It also drops the quotes around those arguments. However, when running the parsed command through spawn on Windows, Node.js will not quote the arguments by default. At the time, in order get around this, Collector quotes all the arguments and runs the command in a shell on Windows. This variation can be avoided by setting the windowsVerbatimArguments to false. That should allow us to run commands without the shell by default. It should also fix issues with quoting being different across platforms. So this issue is partly a bug fix and partly an improvement.

When the shell is enabled, the quotes around arguments should be preserved. Thus, it's up to the user to enter the arguments correctly. On Windows, it may still be necessary to adjust the quotes for arguments that don't need to be quoted on Linux. (For example, we may want to make sure that the primary command is always quoted if it contains spaces). But, generally, it should behave the same.