Add capability to read updates to the scan path during a simulation

[stvdwtt]

ROS will output something that looks like an "event series" format for adamantine to read.

[stvdwtt]

From today's meeting the desired behavior is for adamantine to load the scan path file, run until the end of the commands in that file and then reparse the file to see if new lines have been appended. If they have then it simulates the appended scan path. If not, then it waits and then reparses the file.

[stvdwtt]

Partially addressed by #291. The next step is to extend the scan path syntax to communicate whether more scan path updates are expected or not.