C# Scripting 1.0.0

Major rewrite: different syntax for defining and calling scripts, per-campaign scripts, more helper globals etc. See the README for details.

WARNING: scripts written for csx 0.1.0 and 0.2.0 have to be ported to work with the new version. Given a script such as:

// test.csx
foreach (var arg in Arguments) Log.WriteLine(arg);

the easiest way to adapt it is to wrap it in a params function:

// test.csx
void test(params string[] Arguments) {
  foreach (var arg in Arguments) Log.WriteLine(arg);
}