Ability to set a low limit for Elasticsearch date histogram interval

closes #2901

public/app/plugins/datasource/elasticsearch/partials/query.options.html

@@ -1,4 +1,22 @@
 <section class="grafana-metric-options">
+	<div class="tight-form">
+		<ul class="tight-form-list">
+			<li class="tight-form-item tight-form-item-icon">
+				<i class="fa fa-wrench"></i>
+			</li>
+			<li class="tight-form-item">
+				Group by time interval
+			</li>
+			<li>
+				<input type="text" class="input-medium tight-form-input" ng-model="panel.interval" ng-blur="get_data();"
+							 spellcheck='false' placeholder="example: >10s">
+			</li>
+			<li class="tight-form-item">
+				<i class="fa fa-question-circle" bs-tooltip="'Set a low limit by having a greater sign: example: >60s'" data-placement="right"></i>
+			</li>
+		</ul>
+		<div class="clearfix"></div>
+	</div>
 	<div class="tight-form last">
 		<ul class="tight-form-list">
 			<li class="tight-form-item tight-form-item-icon">