bundlespec: drop externalnames flag
Always provide the human readable version of compression and version.
Add the translated wire format name in the new wirecompression and
wireversion fields.
Differential Revision: https://phab.mercurial-scm.org/D3392
.. Common link and substitution definitions.
.. |hg(1)| replace:: **hg**\ (1)
.. _hg(1): hg.1.html
.. |hgrc(5)| replace:: **hgrc**\ (5)
.. _hgrc(5): hgrc.5.html
.. |hgignore(5)| replace:: **hgignore**\ (5)
.. _hgignore(5): hgignore.5.html