Added slider block view for listingblock.

no longer :construction:
##### todo
 - [x] Only register view if ftw.contentpage is installed
 - [x] Make settings (auto-slide, slide-speed, effect, usw...) configureable in ListingBlock
 - [x] Update styling
 - [x] Update readme; add description how this works with ftw.contentpage
 - [x] Remove debugging stuff from buildout configuration (`development.cfg` and `sources.cfg`)
This link is broken (missing `>`) and will cause trouble when trying to release the package. Use `rst2html` to check RST syntax: 
![rst2html](https://cloud.githubusercontent.com/assets/405124/3568161/5ab6759e-0b2b-11e4-90aa-dc3ac116323c.png)