report the actual url as request_url

Reporting the hash turns (for me) out to be error prone as I do not get the actual host.
move the validations for error_class and environment from Err to Problem

Problems are the models rendered in the UI now, not Errs. Errs are functioning as a glorified hash table. It makes more sense to validate problems.

Also, this paves the way for the next commit, so that no functionality is lost in the subsequent refactor.
Errs are like a hash table whose values are arrays of notices and whose keys are a composite of error_class + component + action + environment + backtrace[0..3].

These fields no longer need to be cached separately on Err because they are now cached on Problem.

This commit combines all those values into one simple key: fingerprint. This should:

 - Make err lookups faster
 - Make it easier to reason about, test, and replace the fingerprint algorithm
 - Make the relationship between Problems, Errs, and Notices clearer
Added jira as new issue tracker
Much nicer looking HipChat notification message
Move some test view in spec/views instead of render_views in
spec/controllers
Move the spec about apps/show.atom.builder in his own spec
Avoid require issue_tracker model directly in Gemfile when it's not
needed
Update javascript-stacktrace to tag 0.5.3.
Adds current user information to notifier.js
Merge pull request #523 from aliscott/javascript-stacktrace-0.5.3

Update javascript-stacktrace to tag 0.5.3.
Merge pull request #524 from roryf/master

Adds current user information to notifier.js
Merge branch 'master' of github.com:errbit/errbit
add javascript notifier changelog [ci-skip]
Merge pull request #516 from xenji-feature/jira-issue-tracker

Conflicts:
	Gemfile.lock
add jira issue tracker on changelog [ci-skip]
add documentation about Jira issue tracker integration
update some gem and fix issue with travis
fix issue with timecop gem and ruby 1.8.7
fix all warning deprecation from rspec 2.14