[glom/f22] (5 commits) ...Tighten library dependencies with the _isa macro

[Kalev Lember]

Summary of changes:

  fc54b61... Update to 1.28.4 (*)
  af83a4a... Simplify macro usage (*)
  20cbb43... Drop huge ChangeLog file (*)
  56e4bc0... Use license macro for the COPYING file (*)
  963fdec... Tighten library dependencies with the _isa macro (*)

(*) This commit already existed in another branch; no separate mail sent