Adds new function to interface to retrieve all enabled currency data from exchange

Implements on alphapointhttp.go
Adds new page to UI to handle exchange balances

wallet.go

@@ -0,0 +1,13 @@
+package main
+
+//ExchangeAccountInfo : Generic type to hold each exchange's holdings in all enabled currencies
+type ExchangeAccountInfo struct {
+	Currencies []ExchangeAccountCurrencyInfo
+}
+
+//ExchangeAccountCurrencyInfo : Sub type to store currency name and value
+type ExchangeAccountCurrencyInfo struct {
+	CurrencyName string
+	TotalValue   int
+	Hold         int
+}