Synchronize grammar for namespace-name#618

Merged

zygoloid merged 2 commits intocplusplus:masterfrom

Eelis:grammarfixes

Mar 7, 2016

Commits on Feb 10, 2016

[gram.key] Make BNF for namespace-name the same as in [gram.dcl] and [namespace.def].
Eelis
committed
[gram.key] Remove unreferenced original-namespace-name nonterminal.
Eelis
committed