Routing enhancement

Added some new features to the routing object:

- Bottle can now be used in a subdirectory natively: the routes will apply from the bottle subdirectory.
- The matching regexp for URI params has changed. It’s now possible to have a route like '/news/:id-:slug.html'. In order to use underscores in a route definition, this char is not allowed anymore in URI param name.
- GET params can now be used with Bottle routing. e.g. a '/news/1-slug.html?key=val' correctly matches the previous route.