Fix bug with IE11

add cache control to none, and do not display overflow, in addition it
need to adjust security settings to allow to get updates and send
commands

Author: luc-github

esp8266/data/printer.tpl

@@ -13,7 +13,7 @@ $INCLUDE[header.inc]$
 </td></tr></table></div></td></tr>
 <tr><td style="padding:0px;"><div id="Bed" style="visibility:hidden;height:0px;">
 <table><tr><td><label>Bed:</label></td>
-<td id="data_bed"></td><td>0<input id="rangeinputbed" type="range" min=0 max=130 onchange="Updatenumber('bed');">130</td>
+<td id="data_bed" style="overflow: hidden;"></td><td>0<input id="rangeinputbed" type="range" min=0 max=130 onchange="Updatenumber('bed');">130</td>
 <td><input class="form-control" id="numberinputbed"type="number" min=0 max=270 step=1 value=0 onchange="Updaterange('bed');"></td><td>&#176;C
 <input type="button" class="btn btn-primary" value="Set" onclick="SendValue( 'M140 S', 'bed');">
 </td></tr></table></div></td></tr>

esp8266/webinterface.cpp

@@ -2561,6 +2561,7 @@ void handle_web_interface_status()
 	}
 	buffer2send+="]";
 	buffer2send+="}";
+	web_interface->WebServer.sendHeader("Cache-Control", "no-cache");
 	web_interface->WebServer.send(200, "application/json",buffer2send);	
 }
 
@@ -2651,6 +2652,7 @@ void handleUpdate(){
 	jsonfile+=intTostr(web_interface->_upload_status);
 	jsonfile+="\"}";
 	//send status
+	web_interface->WebServer.sendHeader("Cache-Control", "no-cache");
 	web_interface->WebServer.send(200, "application/json", jsonfile);
 	//if success restart
 	if (web_interface->_upload_status==UPLOAD_STATUS_SUCCESSFUL)web_interface->restartmodule=true;
@@ -2705,6 +2707,7 @@ void handleFileList() {
 	jsonfile+="\"";
 	jsonfile+="}";
 	path = "";
+	web_interface->WebServer.sendHeader("Cache-Control", "no-cache");
 	web_interface->WebServer.send(200, "application/json", jsonfile);
 }
 
@@ -2722,6 +2725,7 @@ void handleSDFileList() {
 		jsonfile+="\"}";
 	}
 	jsonfile+="]";
+	web_interface->WebServer.sendHeader("Cache-Control", "no-cache");
 	web_interface->WebServer.send(200, "application/json", jsonfile);
 }