#29 extra parsing of files in non-multijava mode

[David Cok]

In code such as this

> public class RAC {
>
> public static void main(String[] args) {
>         //@ assert args.length == 0;
>         System.out.println(args.length);
>         m(1);
> }
>
> public static void m(int i) {
>         //@ assert i == 0;
>         System.out.println("I = " + i);
> }
>
> }

MJC will look in a file m.java for additional external declarations.

It does this when used by jmlrac even when multijava mode is off.

I worked-around this with changes to CClassContext.java
JMethodCallExpression.java JTypeDeclaration.java Main.java that
avoid some attempts to resolve external functions. This solves my
immediate problem, but someone should implement a better
solution and check for other locations that should include checks
for the multijava mode. It appears that the non-multijava mode is
now faster as well, but I did not actually measure performance.