Fixes to goals/totals/etc.

For the most part, this is an update to rename methods to match their updated designs. In the process, the correct values replaced some incorrect ones.

Specifics:
* `total_donated` is the amount (in cents) from donations, including real-time. This does not include community contributions
* `total_raised` is the amount (in cents) from donations and community contributions
* `total_cost` is the amount (in cents) of the fund raising goal + the community contributions (i.e. the sticker price on whatever is being bought/built)
* `percent_xxx` is the amount as a percentage of the total cost
* moved `humanize_amount` into a template tag; renamed to `humanize_cents`

Before/Afters:
![screen shot 2014-12-26 at 11 58 58 am](https://cloud.githubusercontent.com/assets/326918/5558683/9ded0f06-8cf6-11e4-903c-0c5e63cf38f7.png)
![screen shot 2014-12-26 at 11 59 22 am](https://cloud.githubusercontent.com/assets/326918/5558684/a9de71e2-8cf6-11e4-9eb3-8ab7c6d617bc.png)
---
![screen shot 2014-12-26 at 12 00 01 pm](https://cloud.githubusercontent.com/assets/326918/5558687/c9250b92-8cf6-11e4-8ed9-3445850900bd.png)
![screen shot 2014-12-26 at 12 00 11 pm](https://cloud.githubusercontent.com/assets/326918/5558688/c92852a2-8cf6-11e4-98e1-465bd7831347.png)
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![screen shot 2014-12-26 at 12 00 41 pm](https://cloud.githubusercontent.com/assets/326918/5558693/e2201204-8cf6-11e4-9548-dbef16a4ff6e.png)
![screen shot 2014-12-26 at 12 02 46 pm](https://cloud.githubusercontent.com/assets/326918/5558700/2a2e6334-8cf7-11e4-943f-8b35d550bc03.png)