C# console app rehashed as a useful UA parsing tool

The console app in the C# solution was hard-coded to a single demo case. This pull request proposes to turn it into a useful and dynamic utility. It now accepts UA strings (one per line) from standard input, parses them and then emits the identified agent, operating system and device for UA each string. Because it just uses standard input, one can also pipe a file of UA strings for ad-hoc testing.