add OpenType fonts

Would be nice to have OpenType fonts since we have OpenType shaper.
This pull request adds some OpenType fonts from http://www.glukfonts.pl. These fonts are under Open Font License and I have direct permission from the author:

```
Hi ,
You have my permission to include my fonts into Mapnik project.
It would be nice, if You include text of OpenFontLicense in OFL_License.txt too.

Regards,
Grzegorz (gluk)
www.glukfonts.pl
```
I will then create visual test for them as part of https://github.com/mapnik/mapnik/pull/2536.


Foglihtenn:
![text-font-features-500-500-2 0-agg-foglihtenn](https://cloud.githubusercontent.com/assets/1950911/5013891/9595c6d6-6a91-11e4-85e6-d35e9131adc7.png)

Resagokr:
![text-font-features-500-500-2 0-agg-resagokr](https://cloud.githubusercontent.com/assets/1950911/5013889/957e30fc-6a91-11e4-95c4-5844ca12a009.png)

Rawengulk:
![text-font-features-500-500-2 0-agg-rawengulk](https://cloud.githubusercontent.com/assets/1950911/5014064/f2abe8fe-6a92-11e4-9f5e-3c31b2606394.png)

Mikodacs:
![text-font-features-500-500-2 0-agg-mikodacs](https://cloud.githubusercontent.com/assets/1950911/5013884/9579cf44-6a91-11e4-84ba-fcf5aff55c10.png)