Add per-project and per-swimlane task limits

This change allows projects and swimlanes to be configured with task limits that apply to their whole scope (i.e. all active tasks in a project or swimlane, respectively), as opposed to the usual per-column task limits.

app/Template/header/title.php

@@ -7,6 +7,9 @@
             <?= $this->url->link($this->text->e($project['name']), 'BoardViewController', 'show', array('project_id' => $project['id'])) ?>
         <?php else: ?>
             <?= $this->text->e($title) ?>
+            <?php if (! empty($project) && $project['task_limit'] && array_key_exists('nb_active_tasks', $project)): ?>
+              (<span><?= intval($project['nb_active_tasks']) ?></span> / <span title="<?= t('Task limit') ?>"><?= $this->text->e($project['task_limit']) ?></span>)
+            <?php endif ?>
         <?php endif ?>
     </span>
     <?php if (! empty($description)): ?>