Fixing 'this' to refer to the sketch in main methods.

In top level methods, `this` does not work correctly
IE
```java
void setup() {
  println("running test");
  test();
  test = test.bind($p);
  test();
}

void test() {
  try { 
    this.printout(); 
  } catch(Exception e) {
    e.printStackTrace();
  }
}

void printout() {
  println("hello!");
}
```
Currently throws an exception the first time, but not the second time.
If we add `method = method.bind($p)` after every function, it appears to work correctly. However, variables still aren't playing nice. Is this something anyone else has issues with? Will this cause issues in other ways?