Add more detailed script errors

Would make an error like this:
```
var releaseNotes = ParseReleaseNotes("./ReleaseNotes.md" "Allan");
```
generate error like
```
Info: error CS1003: Syntax error, ',' expected
Location: SourceLocation(@116:58)""Allan""
```
instead of just
```
Error: (111,58): error CS1003: Syntax error, ',' expected
```