Add do_call macro, implement Bool builtins, add tests

* I noticed that `fn call(...)` in all objects was identical, so I made
  a macro for it. This should make things a little easier to read, since
  do_call is about 30 lines a pop.
* Bool has a constructor now, and a to_int and to_float implementations
* Add tests for constructors and add new bool tests

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

tests/bool.npp

@@ -0,0 +1,72 @@
+# Bool type operator and function tests
+
+a = true
+b = false
+
+# __not__
+println("__not__")
+println(!a)
+println(!!a)
+println(!!!a)
+println(!!!!a)
+println(!b)
+println(!!b)
+println(!!!b)
+println(!!!!b)
+
+# __and__
+println("__and__")
+println(a && b)
+println(b && a)
+println(a && a)
+println(b && b)
+
+# __or__
+println("__or__")
+println(a || b)
+println(b || a)
+println(a || a)
+println(b || b)
+
+# __eq__
+println("__eq__")
+println(a == a)
+println(a == b)
+println(b == b)
+println(b == a)
+println(a == true)
+println(true == a)
+println(a == false)
+println(false == a)
+println(b == true)
+println(true == b)
+println(b == false)
+println(false == b)
+
+# __ne__
+println("__ne__")
+println(a != a)
+println(a != b)
+println(b != b)
+println(b != a)
+println(a != true)
+println(true != a)
+println(a != false)
+println(false != a)
+println(b != true)
+println(true != b)
+println(b != false)
+println(false != b)
+
+# constructor
+println("constructor")
+println(Bool(""))
+println(Bool(0))
+println(Bool(0.0))
+println(Bool(false))
+# This is a fun one. Bool constructor does *not* parse bools, it just checks if they are empty.
+println(Bool("false"))
+println(Bool("true"))
+println(Bool(1))
+println(Bool(1.0))
+println(Bool(true))