Added track-window settings

<template>

<div id="appSettings">

  <div class="uk-child-width-1-2" uk-grid>

  <p><label><input v-model="disableStream" class="uk-checkbox" type="checkbox"> Disable stream</label></p>

    <p><label class="uk-disabled"><input v-model="autoGpuPreview" class="uk-checkbox" type="checkbox"> GPU preview</label></p>

  <div class="uk-child-width-1-2" uk-grid>

    <p><label><input v-model="autoGpuPreview" class="uk-checkbox" type="checkbox"> GPU preview</label></p>

    <p><label><input v-model="trackWindow" class="uk-checkbox" type="checkbox"> Track window</label></p>

  </div>

</div>

      },

      set(value) {

        this.$store.commit("changeSetting", ['autoGpuPreview', value]);

        this.$root.$emit('globalTogglePreview', value)

      }

    },

    trackWindow: {

      get() {

        return this.$store.state.settings.trackWindow;

      },

      set(value) {

        this.$store.commit("changeSetting", ['trackWindow', value]);

        if (this.$store.state.settings.autoGpuPreview == true) {

          this.$root.$emit('globalTogglePreview', true)

        }

      }

    }

  }