[TASK] Add balance_change array to transaction response, computed from metadata

Reasons to change:
1. No semicolon at the end of a function declaration is a well-accepted standard. Following it will potentially prevent confusion (keeping in mind that this is open source and we aren't the only ones who will be looking at this code).
2. It looks like other ripple projects do not have semicolons at the end of function declarations.
3. JSHint does provide good style enforcement for semicolons *if* you follow the standard. On the other hand, if we diverge from the standard, we get no enforcement at all. This means we can't enforce semicolons at the end of functions *and* we can't enforce not having semicolons at the end of if/for blocks, double semicolons at the end of lines, or any other random semicolons.

Reasons not to change:
1. It requires some effort.

Given that the effort required is minimal (and probably less than the effort of changing all the other ripple projects for consistency) and we are going to have to be fixing a bunch of other jshint errors anyways, it seems that changing makes sense.