Add currency management

app/src/main/java/net/pokeranalytics/android/util/extensions/NumbersExtension.kt

@@ -2,6 +2,7 @@ package net.pokeranalytics.android.util.extensions
 
 import java.text.DecimalFormat
 import java.text.NumberFormat
+import java.util.*
 
 
 // Double
@@ -18,11 +19,16 @@ fun Double.formatted(): String {
     return format.format(this)
 }
 
-fun Double.toCurrency(): String {
-    val format = NumberFormat.getCurrencyInstance()
-    format.maximumFractionDigits = 2
-    format.minimumFractionDigits = 0
-    return format.format(this)
+fun Double.toCurrency(currency: Currency? = null): String {
+
+    val currencyFormatter = NumberFormat.getCurrencyInstance()
+	currency?.let {
+		currencyFormatter.currency = currency
+	}
+
+    currencyFormatter.maximumFractionDigits = 2
+    currencyFormatter.minimumFractionDigits = 0
+    return currencyFormatter.format(this)
 }
 
 fun Double.formattedHourlyDuration() : String {