Update Rails::ActionTimerFilter.filter logging path

Controller.controller_name strips out module name, so all controllers
go into one namespace. This restores namespacing and transforms them
to Graphite namespace nomenclature (. instead of /).
Limit range of eventmachine gem versions

For right now, this is using ruby 1.8.7 and eventmachine 0.15+
requires 1.9.2+
Limit Guard and Guard-Rspec versions for 1.8.7 compatibility
Add tests for ActionTimerFilter
Bump to 0.9.0 due to functionality change
Merge pull request #4 from dgolombek/master

Update Rails::ActionTimerFilter.filter logging path