throttle email notificatiions
use super instead of read_attribute
Merge pull request #308 from lest/patch-1

Cherry-picked #284 to the current master 
extract Problem#comments_allowed? method
move duplicated link outside condition
move comment textarea style to css
simplify urls on problems/show view
Merge pull request #309 from lest/patch-1

Cleanup problems/show view
remove unused yield from layout

Seems it was accidentally added in 02130572aa4dfa420d259b8a15cd26c88b538c45.
simplify powered by in footer
Merge pull request #310 from lest/patch-1

Cleanup layouts/application
extract IssueTracker#configured? and NotificationService#configured?

App is not responsible to know implementation details of issue trackers
and notification services.
simplify class checking for issue tracker and notification service
Changed image links in css files to use relative urls
Merge pull request #311 from bjpe/relative_image_url

Changed image links in css files to use relative urls
Working on Gitlab integration
Working on Gitlab integration
Updated README for Gitlab information
Upgrading was missing bundle install call

Since dependencies may have changed, must call bundle install
Merge pull request #313 from Iristyle/patch-1

Upgrading was missing bundle install call