Update shared files to latest among other slim projects

* lib/slimtimer/api.rb from dashboard
* models/* from slim-reports
Bundle sinatra-contrib 1.3.2

For 'sinatra-content-for' from slim-reports
Import slim-reports code
Change slim-reports to inherit from Sinatra::Base
Move slim-plus assets into subdirectory
Import slim-reports assets
Change slim-reports layout to use asset subdirectory for css/js
Add example routes config for SlimReportsWeb