Revision 460621

Flavorize and modernize Emacs ports

- Convert USE_EMACS to USES=emacs
- Remove editors/emacs-nox11 (refer to nox flavors of editors/emacs and
  editors/emacs-devel)
- Permit default Emacs flavor to be specified in make.conf
- Rename japanese/migemo-emacs23 to japanese/migemo-emacs
- Update and simplify audio/emms and fix build on FreeBSD 10 [1]
- Update databases/bbdd and fix build on FreeBSD 10 [1]
- Update editors/emacs-devel
- Ensure Makefile shell commands that change directory are executed in a
  subshell
- Silence some portlint warnings

[1] By not depending on base texinfo

PR:		225404
Reviewed by:	antoine
Approved by:	portmgr (mat) ashish (maintainer)
Differential Revision:	https://reviews.freebsd.org/D13506