Temporarily disable type parameters that are themselves tuples

On 0.4, we can't differentiate between these and tuples of types that
were saved by earlier versions of Julia. In earlier versions of Julia,
such tuples were not bits typed so they would not have been usable
anyway. We can revisit this when we're ready to change the file format
(perhaps as part of #204/#218)

src/JLD.jl

@@ -834,13 +834,15 @@ function full_typename(io::IO, file::JldFile, tv::TypeVar)
         print(io, ')')
     end
 end
-function full_typename(io::IO, file::JldFile, jltype::@compat Tuple{Vararg{Type}})
-    print(io, '(')
-    for t in jltype
-        full_typename(io, file, t)
-        print(io, ',')
+if VERSION < v"0.4.0-dev+4319"
+    function full_typename(io::IO, file::JldFile, jltype::@compat Tuple{Vararg{Type}})
+        print(io, '(')
+        for t in jltype
+            full_typename(io, file, t)
+            print(io, ',')
+        end
+        print(io, ')')
     end
-    print(io, ')')
 end
 function full_typename(io::IO, ::JldFile, x)
     # Only allow bitstypes that show as AST literals and make sure that they
@@ -849,7 +851,7 @@ function full_typename(io::IO, ::JldFile, x)
     # A different implementation will be required to support custom immutables
     # or things as simple as Int16(1).
     s = sprint(show, x)
-    if isbits(x) && parse(s) === x
+    if isbits(x) && parse(s) === x && !isa(x, Tuple)
         print(io, s)
     else
         error("type parameters with objects of type ", typeof(x), " are currently unsupported")