Fixed routing for *_tpl controllers

Dangling slashes were causing routing mistakes on *_tpl controllers.
Some requests were mistakenly routed as generic mixins, e.g.:

GET /mixin/os_tpl/debian6/  ->  MixinController

instead of

GET /mixin/os_tpl/debian6/  ->  OsTplController
Merge pull request #9 from arax/tpl_routing_fix

Fixed routing for *_tpl controllers