IO-1612 Add employee vacation tracking.

client/src/translations/es/common.json

@@ -833,6 +833,7 @@
 		},
 		"employees": {
 			"actions": {
+				"addvacation": "",
 				"new": "Nuevo empleado",
 				"newrate": ""
 			},
@@ -854,10 +855,16 @@
 				"pin": "",
 				"rate": "",
 				"termination_date": "Fecha de conclusión",
-				"user_email": ""
+				"user_email": "",
+				"vacation": {
+					"end": "",
+					"length": "",
+					"start": ""
+				}
 			},
 			"labels": {
 				"actions": "",
+				"endmustbeafterstart": "",
 				"flat_rate": "",
 				"name": "",
 				"rate_type": "",