taking into account TESTNAME variable in reftest (see #41)
Store the arrays of properties as &'static [T] rather than [T, ..N].

This means the .as_slice() call (which is problematic when storing the array
in a static struct) is no longer necessary.
Introduce a NativeProperties struct to store the properties.

This will simplify adding more kinds of properties, such as static attributes.
Pass the NativeProperties struct to CreateInterfaceObjects2.

This will simplify adding more kinds of properties, such as static attributes.
Use internal mutability for Attr::value.
Fix warning in gfx: "variable does not need to be mutable"
Merge pull request #2695 from Ms2ger/NativeProperties

Introduce a NativeProperties struct; r=jdm
Merge pull request #2696 from saneyuki/fix_warn

Fix warning in gfx: "variable does not need to be mutable"; r=Ms2ger
Merge pull request #2681 from saneyuki/attr

Use internal mutability for Attr::value; r=jdm
Remove "DerefMut" implementation from Root/JSRef.
Remove needless mutabilities from script crate.
Merge pull request #2691 from schaars/testname

taking into account TESTNAME variable in reftest (see #41)
Merge pull request #2697 from saneyuki/js

Remove "DerefMut" implementation from Root/JSRef; r=jdm
Introduce static makeNativeName methods to share code with the upcoming static members.
Implement static methods (fixes #1989).
Implement static attributes (fixes #1989).
Merge pull request #2699 from Ms2ger/static-methods

Implement static IDL members; r=jdm