Add reverse sorting on commitfest page

[destrex271]

Implements reverse sorting in the columns of the commitfest pages.

This is a cleaned up version of #28 and #32

Fixes #20

[destrex271]

@JelteF I think this should do it

[JelteF]

The logic works well, but the html template should be changed here:

pgcommitfest/pgcommitfest/commitfest/templates/commitfest.html

Lines 63 to 74 in 0f23363

	<th><a href="#" style="color:#333333;" onclick="return sortpatches(5);">Patch</a>{%if sortkey == 5%}<div style="float:right;"><i class="glyphicon glyphicon-arrow-down"></i></div>{%endif%}</th>
	<th><a href="#" style="color:#333333;" onclick="return sortpatches(4);">ID</a>{%if sortkey == 4%}<div style="float:right;"><i class="glyphicon glyphicon-arrow-down"></i></div>{%endif%}</th>
	<th>Status</th>
	<th>Ver</th>
	<th>CI status</th>
	<th><a href="#" style="color:#333333;" onclick="return sortpatches(6);">Stats</a>{%if sortkey == 6%}<div style="float:right;"><i class="glyphicon glyphicon-arrow-down"></i></div>{%endif%}</th>
	<th>Author</th>
	<th>Reviewers</th>
	<th>Committer</th>
	<th><a href="#" style="color:#333333;" onclick="return sortpatches(3);">Num cfs</a>{%if sortkey == 3%}<div style="float:right;"><i class="glyphicon glyphicon-arrow-down"></i></div>{%endif%}</th>
	<th><a href="#" style="color:#333333;" onclick="return sortpatches(1);">Latest activity</a>{%if sortkey == 1%}<div style="float:right;"><i class="glyphicon glyphicon-arrow-down"></i></div>{%endif%}</th>
	<th><a href="#" style="color:#333333;" onclick="return sortpatches(2);">Latest mail</a>{%if sortkey == 2%}<div style="float:right;"><i class="glyphicon glyphicon-arrow-down"></i></div>{%endif%}</th>

It needs to show glyphicon-arrow-up for the reverse sort.

[destrex271]

done

[JelteF]

I pushed two small changes to this branch and merged it. FYI for next time it was failing the formatting/linting checks. You can run those locally using make fix.

[JelteF]

Thanks for the contribution.