Fix error locations.

[AskingQuestions]

Most parsers are giving errors that are based on their parent position.

Carbonite example

class Abc { // <- Parse error is here
   void xyz(int parseErr@r) { // <- Parse error should be here

  }
}

The problem is in error bubbling, each error should keep track of its children, and then the parser should decide the error location.

[AskingQuestions]

The commit 40ae4b1 adds some more limited location detail. Simply tracking error depth and picking the deepest if the parse fails. As you might notice this is fairly naive and may lead to errors that are way off, that said, its a step up from the current error tracking and should help a little.

The next steps would be to build a more robust tracking system in the future, however a rewrite seems due and would automatically fix this issue.

Parsing performance should not be effected, but a few things were changed in this update that may break things.

It may take a while for this new feature to propagate to carbonite and carpeg itself, as our pipeline is not as feature full as it should be.