[isabelle-dev] NEWS

[Makarius]

* Name space merge now observes canonical order, i.e. the second space
is inserted into the first one, while existing entries in the first
space take precedence.  INCOMPATIBILITY in rare situations, may try to
swap theory imports.

* Authentic naming of facts disallows ad-hoc overwriting of previous
theorems within the same name space.  INCOMPATIBILITY, need to remove
duplicate fact bindings, or even accidental fact duplications.  Note
that tools may maintain dynamically scoped facts systematically, using
PureThy.add_thms_dynamic.