Use javascript_include_tag helper to include javascript

Use Rails helper to include javascript. Assets pipeline divides manifest into separate files if assets.debug is true
Add directions to CONTRIBUTING for common mistake when running tests
Fix i18n for boolean filter (also fixes #2170)

Similar to commit 47fe4c5 but fixes regression that caused untranslated
labels for boolean filters.
Merge pull request #2221 from dmfrancisco/pr-fix-boolean-filter-i18n

Fix i18n for boolean filter (updates the fix for #2170)
improve test perf by deferring garbage collection

Our tests run noticeably faster by only running garbage collection every 15 seconds.
Inspired by: ariejan.net/2011/09/24/rspec-speed-up-by-tweaking-ruby-garbage-collection
modularize the search method dropdown for the filter form
fix Rails 4 problem with form builder ("undefined method `upcase'")

In Rails 4, ActiveRecord::Base#model_name no longer returns a string, but an ActiveModel::Name object, see https://gist.github.com/brupm/4544950. Calling #to_s on this object is a Rails3-compatible workaround for this change.
Merge pull request #2215 from tank-bohr/master

Include JS in layout with rails helper
remove redundant set of tests

This code almost exactly mirrors the tests abve it. The only difference
being that this uses `button_html` while the other uses `label` when
dealing with `f.action`.

We shouldn't be testing Formtastic's public API, so I'm removing the
second set of tests.
add test to ensure that form attribute labels are translated

for #2012