[bug] Type aliases don't work properly with 'using namespace'

[IsaacShelton]

main.adept

import basics
import "other.adept"

func main {
    x custom\integer = doSomething()
}

other.adept

using namespace custom

namespace custom {
    alias integer = int
}

func doSomething() integer = 10

[IsaacShelton]

Removed using namespace, see #58 for explanation

This bug is out of date since the recent removal of using namespace