Fix arguments for hevercardable helper

We should pass person object to the hovecrardable helper. In the
current case `this` is the status message, not the status
author. So, let's pass `author` instead of `this`.
Tests for hovercard in reshares

Coverage with tests is necessary for every feature
Use capybara hover method in the hovercard steps

Let's use methods provided by capybara whenever possible.
Make step name more logical
Make feature consistent with other features.

Actually, I just trying to make this feature pass.
Check user name presence instead

It seems that loading of stream is not completed before trying to activate hovercard.
I do not want to add explicit pause to the scenarion. Let's check link presence before activating hovercard.
I added the validation for blank to poll question and poll answer
Unescape text before add mention, this commit solve #4776
Rake task for running outstanding account deletions
Remove hack from exporter

I couldn't reproduce what the comment states anymore, so I just removed
it. This fixes a minor issue where html wouldn't be escaped in the
export.

Thanks to A Kai (@sixhundredns) for reporting.
Render flash message content with .text

.html does not escape any html input in these, leading to XSS
attack vectors.

Thanks to A Kai (@sixhundredns) for reporting the related issues.
Replace vaild with valid

Thanks to Josias for the hint
Merge pull request #4919 from hpetru/4776-mention-on-mobile

Unescape text before add mention, this commit solve #4776

Conflicts:
	Changelog.md
Merge pull request #4916 from hpetru/validate-poll-answer

I added the validation to poll question and poll answer

Conflicts:
	app/assets/javascripts/app/views/publisher_view.js
Merge pull request #4758 from bronislav/feature/4724-remove-own-hovercard-popup-in-reshares

[WIP] Fix hovercard in reshares
Add changelog entry for #4758 [ci skip]
Merge pull request #4963 from Ruxton/feature/rake_task_to_run_account_deletion_fixes_4792

Rake task for running outstanding account deletions
Use toggle() to hide the poll creator
Remove debug puts