add note for devels to not forget on headpin

it happen too often that only
 %files
is changes and
 %files headpin
is forgotten
add rubygem-rkerberos to foreman comps

addressing:
Error: Package: foreman-proxy-1.2.9999-1.201306071242gitc4a245d.fc18.noarch (katello-foreman)
           Requires: rubygem(rkerberos)
add rubygem-po_to_json to foreman comps

addressing:
Error: Package: rubygem-gettext_i18n_rails_js-0.0.8-1.fc18.noarch (katello-foreman)
           Requires: rubygem(po_to_json) >= 0.0.7
add rubygem-gettext_i18n_rails to foreman comps for F18

addressing:
Error: Package: rubygem-gettext_i18n_rails_js-0.0.8-1.fc18.noarch (katello-foreman)
           Requires: rubygem(gettext_i18n_rails) >= 0.7.1
           Installed: rubygem-gettext_i18n_rails-0.6.6-2.fc18.noarch (@updates)
               rubygem(gettext_i18n_rails) = 0.6.6
           Available: rubygem-gettext_i18n_rails-0.6.6-1.fc18.noarch (fedora)
               rubygem(gettext_i18n_rails) = 0.6.6

adding just to F18, because we already have it in el6. And in F19 is rubygem-gettext_i18n_rails-0.9.4-1.fc19 which is >= 0.7.1.
add rubygem-highline to foreman rhel6 comps

addressing:
Error: Package: 1:foreman-installer-1.2.9999-1.201306131832git8728197.el6.noarch (katello-foreman)
           Requires: rubygem-highline
Changesets: Fixing changeset tree in Chrome

Fixing changeset sliding tree panel in Chrome. Fixes #2509
Merge pull request #2534 from mptap/chg_sltree_view

Fix: Changeset sliding tree messed up in Chrome
Merge pull request #2515 from xsuchy/pull-req-headpin-note

add note for devels to not forget on headpin
Merge pull request #2528 from xsuchy/pull-req-foreman-comps4

add some packages to foreman comps
Dashboard: Fixing subscription graph in Chrome
Add missing deps into foreman comps

Some additional packages were introduced recently into foreman-proxy
and foreman-installer.
Merge pull request #2536 from iNecas/foreman-comps-fix

Add missing deps into foreman comps
color-search - 1 liter of goodness
color-search - renamed search term from color to status
Merge pull request #2439 from daviddavis/subscription-graph

System subscription status graph intermittently appears misaligned
Add justified package
Gravatar Image - Adding gravatar image to the Katello User Page

1.Defined some methods for pulling gravatar image for the signed in user and
  displayed it on the Katello User Page and modified the header css.

2.Added a config option for users to enable and disable gravatar on
  Katello User Page.

3.Added a method for testing gravatar enable/disable option and
  also defined gravatar as boolean.
Merge pull request #2535 from thomasmckay/color-search

color-search - 1 liter of goodness
Merge pull request #2497 from pgodhani/gravatar_katello

Gravatar Image - Adding gravatar image to the Katello User Page
Add how-to package new gem doc
Merge pull request #2537 from pitr-ch/tdd/justified-rpm

Add justified package && Add how-to package new gem doc