Split out components requiring elevated privileges to run as a service

[JLospinoso]

From this issue: #7

[jdgregson]

This I feel is the most critical change for Beamgun. As it is, an attacker simply needs to close Beamgun before inserting a malicious device, which would realistically take an extra five seconds. The guts of Beamgun should be running in Admin land where the user cannot kill it.

Unfortunately, I don't have any experience writing Windows services, and since I have very limited C# experience, I wouldn't trust myself to write security-critical code in the language.