[TASK] Switch to more consistence Bootstrap grid classes, other issues

Resources/Private/Partials/Backend/Filter.html

 <f:form action="index" controller="Backend" method="post" objectName="filters" object="{filters}">
 	<div class="row">
 		<f:if condition="{showCategoryFilter}">
-			<div class="col-xs-4">
+			<div class="col-sm-4">
 				<div class="form-group">
 					<label for="filter-categories">
 						<f:translate key="backend.filters.categories" />
@@ -11,7 +11,7 @@
 				</div>
 			</div>
 		</f:if>
-		<div class="col-xs-{f:if(condition: showCategoryFilter, then: '4', else: '6')}">
+		<div class="col-sm-{f:if(condition: showCategoryFilter, then: '4', else: '6')}">
 			<div class="form-group">
 				<label for="filter-tags">
 					<f:translate key="backend.filters.tags" />
@@ -20,16 +20,16 @@
 				<small><f:format.raw><f:translate key="backend.filters.tags.description" /></f:format.raw></small>
 			</div>
 		</div>
-		<div class="col-xs-{f:if(condition: showCategoryFilter, then: '4', else: '6')}">
+		<div class="col-sm-{f:if(condition: showCategoryFilter, then: '4', else: '6')}">
 			<div class="form-group">
 				<label for="filter-search"><f:translate key="backend.filters.search" /></label>
 				<f:form.textfield class="form-control" property="search" id="filter-search" />
 			</div>
-			<div class="media">
+			<div class="media-buttons">
 				<div class="pull-right divider">
 					<f:form.button class="btn btn-success form-control" type="submit"><f:translate key="backend.filter" /></f:form.button>
 				</div>
-				<div class="pull-right divider">
+				<div class="pull-right divider" style="margin-right: 15px">
 					<f:form.button id="filter-reset-btn" class="btn btn-danger form-control" type="reset"><f:translate key="backend.filter.reset" /></f:form.button>
 				</div>
 			</div>