bug fix: remove decode for resouce ident when use cherrypy's default dispatcher

Now there are two kinds of sub-collection/resource dispatchers.
1. Use cherrypy's default dispatcher
Cherrypy will decode the ident automatically
But now in kimchi we decode the ident manually.
This is a bug.
Kimchi can not list the resources with unicode name.

For examle:
create a pool with kīмсhī-pool name
list this pool
$ curl -u shhfeng -H 'Accept: application/json' \
-H 'Content-type: application/json' \
http://localhost:8000/storagepools/kīмсhī-pool

kimchi will throw an UnicodeEncodeError.

This patch fixes this bug.

2. customized dispatcher by overriding the cherrypy dispatcher
We need to decode the ident explicitly.
Now kimchi handles it correctly.

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>