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/board/table_container.php

@@ -1,4 +1,5 @@
-<div id="board-container">
+<div id="board-container"
+     class="<?= ($project['task_limit'] && $project['nb_active_tasks'] > $project['task_limit']) ? 'board-task-list-limit' : '' ?>">
     <?php if (empty($swimlanes) || empty($swimlanes[0]['nb_columns'])): ?>
         <p class="alert alert-error"><?= t('There is no column or swimlane activated in your project!') ?></p>
     <?php else: ?>

app/Template/board/table_swimlane.php

@@ -15,7 +15,11 @@
         <?php endif ?>
 
         <span title="<?= t('Task count') ?>" class="board-column-header-task-count swimlane-task-count-<?= $swimlane['id'] ?>">
-            (<?= $swimlane['nb_tasks'] ?>)
+            <?php if ($swimlane['task_limit']): ?>
+                (<?= $swimlane['nb_tasks'] ?>/<?= $swimlane['task_limit'] ?>)
+            <?php else: ?>
+                (<?= $swimlane['nb_tasks'] ?>)
+            <?php endif ?>
         </span>
     </th>
 </tr>

app/Template/board/table_tasks.php

@@ -1,5 +1,5 @@
 <!-- task row -->
-<tr class="board-swimlane board-swimlane-tasks-<?= $swimlane['id'] ?>">
+<tr class="board-swimlane board-swimlane-tasks-<?= $swimlane['id'] ?><?= $swimlane['task_limit'] && $swimlane['nb_tasks'] > $swimlane['task_limit'] ? ' board-task-list-limit' : '' ?>">
     <?php foreach ($swimlane['columns'] as $column): ?>
         <td class="
             board-column-<?= $column['id'] ?>