Create match configurator

As a contributor I would like to be able to offer a match using a configurator, so that I can specify my match parameters.

![match configurator-1](https://cloud.githubusercontent.com/assets/667753/2781098/2e871150-cb10-11e3-8cc1-446f1b0483dd.jpg)

## Be sure to

- [ ] Set date_from limit to today's date, which has to be on or after the project start date
- [ ] Set date_to limit to on or before project finish date
- [ ] Make minimum amount $1,000 for the max amount field