Add blackrock-payments code for referral program

[paulproteus]

• Adjust renderStorage and renderQuantity to add the two numbers
• Display referral bonus on the account level template

[paulproteus]

Responded to @jparyani's comment with the extra commit.

[paulproteus]

Dumb (?) question - are we dogmatic about if to indent the {{# if ... }} and also the thing inside it?

Seems like:

• Indent the {{#if ... } based on personal discretion, and
• Always indent the contents of the {{#if ... }}

So I followed that in a follow-up commit.

[paulproteus]

All fixed, I think.

[kentonv]

HTML indentation is weird because if you indent everything it can get excessively deep. The main rules I'd set are:

• The children of an element/block must always be indented at least as much as the parent, and possibly by one more stop than the parent.
• All siblings should have the same indentation.

Of course, this is all nitpicky. The main thing is it should be legible and not misleading.

[kentonv]

Code looks fine now, will merge after Sandstorm itself is updated.