Added a common util to get project slug.

app/assets/javascripts/lib/common_utils.js.coffee

+((w) ->
+
+  w.gl       or= {}
+  w.gl.utils or= {}
+
+  w.gl.utils.getProjectSlug = ->
+
+    $body = $ 'body'
+    isInProjectPage = $body.data('page').split(':')[0] is 'projects'
+
+    return if isInProjectPage then $body.data 'project' else null
+
+) window