Add Dutch translations

The full Dutch translations. I'm prepared to add future additional translations.

src/locale/lang/nl.js

+export default {
+  el: {
+    datepicker: {
+      now: 'Nu',
+      today: 'Vandaag',
+      cancel: 'Annuleren',
+      clear: 'Legen',
+      confirm: 'Bevestig',
+      selectDate: 'Selecteer datum',
+      selectTime: 'Selecteer tijd',
+      startDate: 'Startdatum',
+      startTime: 'Starttijd',
+      endDate: 'Einddatum',
+      endTime: 'Eindtijd',
+      year: 'Jaar',
+      month1: 'januari',
+      month2: 'februari',
+      month3: 'maart',
+      month4: 'april',
+      month5: 'mei',
+      month6: 'juni',
+      month7: 'juli',
+      month8: 'augustus',
+      month9: 'september',
+      month10: 'oktober',
+      month11: 'november',
+      month12: 'december',
+      // week: 'week',
+      weeks: {
+        sun: 'Zo',
+        mon: 'Ma',
+        tue: 'Di',
+        wed: 'Wo',
+        thu: 'Do',
+        fri: 'Vr',
+        sat: 'Za'
+      },
+      months: {
+        jan: 'jan',
+        feb: 'feb',
+        mar: 'maa',
+        apr: 'apr',
+        may: 'mei',
+        jun: 'jun',
+        jul: 'jul',
+        aug: 'aug',
+        sep: 'sep',
+        oct: 'okt',
+        nov: 'nov',
+        dec: 'dec'
+      }
+    },
+    select: {
+      loading: 'Laden',
+      noMatch: 'Geen overeenkomende resultaten',
+      noData: 'Geen data',
+      placeholder: 'Selecteer'
+    },
+    pagination: {
+      goto: 'Ga naar',
+      pagesize: '/page',
+      total: 'Totaal {total}',
+      pageClassifier: ''
+    },
+    messagebox: {
+      title: 'Bericht',
+      confirm: 'Bevestig',
+      cancel: 'Annuleren',
+      error: 'Ongeldige invoer'
+    },
+    upload: {
+      delete: 'Verwijder',
+      preview: 'Voorbeeld',
+      continue: 'Doorgaan'
+    },
+    table: {
+      emptyText: 'Geen data',
+      confirmFilter: 'Bevestigen',
+      resetFilter: 'Reset',
+      clearFilter: 'Alles'
+    },
+    tree: {
+      emptyText: 'Geen data'
+    }
+  }
+};