add connection cycle option

adds the option to disconnect / reconnect after sending M112.
May help break out of blocking commands by resetting some control boards

octoprint_estop/templates/estop_settings.jinja2

@@ -9,5 +9,12 @@
                 <span class="help-block">Usually this is M112. Only change if you know what you're doing.</span>
             </div>
         </div>
+        <div class="control-group">
+            <label class="control-label">{{ _('Cycle the connection?') }}</label>
+            <div class="controls">
+                <input type="checkbox" class="input-block" data-bind="checked: settings.plugins.estop.estopReconnect">
+                <span class="help-block">Enabling this will attempt to automatically cycle the connection to the printer. This may cause the printer's control board to be reset (may help break out of blocking commands).</span>
+            </div>
+        </div>
     </form>
 </div>