Fluid containers can now be configured via settings

Added UI:

Added checkbox for toggling Bootstrap grid CSS container class to switch between fixed or fluid container behavior under /admin/appearance/settings/bootstrap.

For more info about Bootstrap grid CSS class container-fluid read: http://getbootstrap.com/css/#grid-example-fluid

Before in 7.x-3.0:

Before, there were static classes assigned to containers in page.tpl.php:

Lines 77-78:

<header id="navbar" role="banner" class="<?php print $navbar_classes; ?>">
<div class="container">

Line 117:
<div class="main-container container">

Line 168:
<footer class="footer container">

After in 7.x-3.1:

There is now a $container_class variable that can be used in page.tpl.php files. This is the only template this exists in currently.

Lines 77-78:

<header id="navbar" role="banner" class="<?php print $navbar_classes; ?>">
<div class="<?php print $container_class; ?>">

Line 117:
<div class="main-container <?php print $container_class; ?>">

Line 168:
<footer class="footer <?php print $container_class; ?>">

Other templates

If you need a dynamic container class in other templates, you will need to add it via a preprocess function beforehand using the following theme setting: bootstrap_fluid_container

/**
 *  Implements hook_preprocess_HOOK().
 */
function bootstrap_subtheme_preprocess_HOOK(&$variables) {
  $variables['container_class'] = theme_get_setting('bootstrap_fluid_container') ? 'container-fluid' : 'container';
}