Add a debugger.

Create a debugger model to store metadata about executed database
queries. For each query, store the query literal and the params
(groupped by query literal) and the time taken for execution.

A dummy debugger allows access to the API without slowing down
execution when profiling is disabled.
Call debugger from db model.
Add tests verifying db calls debugger
Proper debugger initialization in base controller
Rename "profiling" controller to "debugging"
Add the special case of word ending in -y to pluralizer
Add basic test suite for pluralizer
Merge branch 'pluralize' into profiling
Profiler UI