Description of problem:

Attempting to access Systems->Registered when tomcat6 (for candlepin) is not running generates an ugly error.  See below.

Version-Release number of selected component (if applicable):
git master

How reproducible:


Steps to Reproduce:
1. sudo /sbin/service tomcat6 stop
2. sdript/rails s
3. got to Systems->Registered in UI
  
Actual results:

rrno::ECONNREFUSED in Systems#index

Showing /home/bbucking/git/katello/src/app/views/systems/_list_system.html.haml where line #9 raised:

Connection refused - connect(2)

Extracted source (around line #9):

6:       - elsif col.to_s == 'created'
7:         = convert_time(item.created)
8:       - elsif col.to_s == 'lastCheckin'
9:         = get_checkin(item)
10:       - else
11:         = item.send(col)
12:   %div

Trace of template inclusion: app/views/systems/_list_systems.html.haml, app/views/common/_panel.html.haml, app/views/systems/index.html.haml

Rails.root: /home/bbucking/git/katello/src
Application Trace | Framework Trace | Full Trace

lib/http_resource.rb:83:in `get'
lib/resources/candlepin.rb:110:in `get'
app/models/glue/candlepin/consumer.rb:25:in `included'
app/models/lazy_accessor.rb:125:in `instance_eval'
app/models/lazy_accessor.rb:125:in `run_initializer'
app/models/lazy_accessor.rb:71:in `lastCheckin'
app/helpers/systems_helper.rb:21:in `get_checkin'
app/views/systems/_list_system.html.haml:9:in `_app_views_systems__list_system_html_haml___2092465704_70238783180780_32924596'
app/views/systems/_list_system.html.haml:2:in `each'
app/views/systems/_list_system.html.haml:2:in `_app_views_systems__list_system_html_haml___2092465704_70238783180780_32924596'
app/views/systems/_list_systems.html.haml:2:in `_app_views_systems__list_systems_html_haml___2076420724_70238783388120_5925588'
app/views/systems/_list_systems.html.haml:1:in `_app_views_systems__list_systems_html_haml___2076420724_70238783388120_5925588'
app/helpers/systems_helper.rb:17:in `render_rows'
app/views/common/_panel.html.haml:46:in `_app_views_common__panel_html_haml__2691000_70238781909580_2069205172'
app/helpers/application_helper.rb:96:in `two_panel'
app/views/systems/index.html.haml:13:in `_app_views_systems_index_html_haml___1100083565_70238782267800_0'
lib/util/threadsession.rb:77:in `thread_locals'


Expected results:
Better error handling.  Perhaps the page comes up without data and displaying error message that service is unavailable.

Additional info: